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Non-English-based programming languages

Non-English-based programming languages are programming languages that do not use keywords taken from or inspired by English vocabulary.

Prevalence of English-based programming languages
The use of the English language in the inspiration for the choice of elements, in particular for keywords in computer programming languages and code libraries, represents a significant trend in the history of language design. According to the HOPL online database of languages, out of the 8,500+ programming languages recorded, roughly 2,400 of them were developed in the United States, 600 in the United Kingdom, 160 in Canada, and 75 in Australia.

Thus, over a third of all programming languages have been developed in countries where English is the primary language. This does not take into account the usage share of each programming language, situations where a language was developed in a non-English-speaking country but used English to appeal to an international audience (see the case of Python from the Netherlands, Ruby from Japan, and Lua from Brazil), and situations where it was based on another programming language which used English.

International programming languages
The concept of international-style programming languages was inspired by the work of British computer scientists Christopher Strachey, Peter Landin, and others. It represents a class of languages of which the line of the algorithmic languages ALGOL was exemplary.

ALGOL 68
ALGOL 68's standard document was published in numerous natural languages. The standard allowed the internationalization of the programming language. On December 20, 1968, the "Final Report" (MR 101) was adopted by the Working Group, then subsequently approved by the General Assembly of UNESCO's IFIP for publication. Translations of the standard were made for Russian, German, French, Bulgarian, and then later Japanese. The standard was also available in. ALGOL 68 went on to become the GOST/ГОСТ-27974-88 standard in the Soviet Union. In English, Algol68's case statement reads case ~ in ~ out ~ esac. In Russian, this reads выб ~ в ~ либо ~ быв.
 * GOST 27974-88 Programming language ALGOL 68 – Язык программирования АЛГОЛ 68
 * GOST 27975-88 Programming language ALGOL 68 extended – Язык программирования АЛГОЛ 68 расширенный

Citrine
Localization is the core feature of the Citrine Programming Language. Citrine is designed to be translatable to every written human language. For instance the West Frisian language version is called Citrine/FY. Citrine features localized keywords, localized numbers and localized punctuation. Users can translate code files from one language into another using a string-based approach. At the time of writing, Citrine supports 111 human languages. Support is not limited to well-known languages; all natural human languages up to EGIDS-6 are being accepted for inclusion.

Hedy
Hedy is an open-source programming language which was developed for programming education. It was designed to be as instructive as possible and as accessible as possible with a few unique features. It supports over 30 different languages, meaning its keywords can be typed in any of those. It supports languages which do not use the Latin alphabet for its keywords and variable names and it also supports more numbering systems than Arabic numerals, like Eastern Arabic numerals. All of these can be used interchangeably. The error messages are quite verbose, explaining what is wrong and what might be a fix, just like the Rust compiler.

Scheme
While internationalization is not a part of any Scheme standard, the expressiveness and flexibility of the language allows for the addition of internationalization as a library. International Scheme is an open source project to which anyone can contribute a translation. Since translations of Scheme can be loaded as libraries, Scheme programs can be multilingual.

Scratch
Scratch is a block-based educational language. The text of the blocks is translated into many languages, and users can select different translations. Unicode characters are supported in variable and list names. (Scratch lists are not stored inside variables the way arrays or lists are handled in most languages. Variables only store strings, numbers, and, with workarounds, boolean values, while lists are a separate data type that store sequences of these values.) Projects can be "translated" by simply changing the language of the editor, although this does not translate the variable names.

Based on symbols instead of keywords

 * APL – A language based on mathematical notation and abstractions.
 * Brainfuck – A minimalist esoteric programming language, created for the purpose of having the smallest possible compiler.
 * Emojicode – An esoteric language based on Emojis.
 * G – Graphical language used in LabVIEW (not to be confused with G-code).
 * Hoon – A systems programming language for Urbit, compiling to Nock.
 * J – An APL-like language which uses only ASCII special characters and adds function-level programming.
 * Light Pattern – A language which uses a series of photographs rather than text as source code.
 * Mouse – A minimalist language created by Peter Grogono which uses ASCII characters for keywords.
 * Piet – An art-based esoteric programming language.
 * Plankalkül – The first high-level non-von Neumann programming language, designed by Konrad Zuse during World War II in Germany.
 * Whitespace – An esoteric language based on whitespace characters (spaces, tabs, and line breaks).

Modifiable parser syntax

 * Babylscript – A multilingual version of JavaScript which uses multiple tokenizers to support localized keywords in different languages and which allows objects and functions to have different names in different languages.
 * Component Pascal – A preprocessor that translates native-language keywords into English in an educational version of the BlackBox Component Builder available as open source. The translation is controlled via a modifiable vocabulary and supported by modifiable compiler error messages. A complete Russian version is used in education, and it should be possible to accommodate other left-to-right languages (e.g., the Kabardian language has been tried as a proof of concept).
 * HyperTalk – A programming language, which allows translation via custom resources, used in Apple's HyperCard.
 * IronPerunis – An IronPython 2.7 localization to Lithuanian and Russian.
 * AppleScript – A language which once allowed for different "dialects" including French and Japanese; however, these were removed in later versions.
 * Maude – Completely user-definable syntax and semantics, within the bounds of the ASCII character set.
 * Perl – While Perl's keywords and function names are generally in English, it allows modification of its parser to modify the input language, such as in Damian Conway's Lingua::Romana::Perligata module, which allows programs to be written in Latin or Michael G. Schwern's Lingua::tlhInganHol::yIghun Perl language in Klingon. They do not just change the keywords but also the grammar to match the language.
 * Perunis – Python 2.6 localization to Lithuanian and Russian.
 * Ioke – Ioke is a folding language. It allows writing highly expressive code that writes code. Examples of same program in Chinese, Danish, Hindi and Spanish

title: Non-English-based programming languages


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Talk:Non-English-based programming languages

To-do list for explanatory intro text
TODO: Disscuss abit about history of programming languages, in relation to the use of english, please somebody who knows about it (I don't), where most langs dev'd by native english speakers? is it just a part of the tendency to use english as a technical language, being technically richer? (as reported in E. Raymond essay)
 * Added some numbers based on the HPOL database... they mark the nation of origin for most languages. Tried to be vague about what I was implying, since I still cannot find a source for analysis of why English is so popular. --Marcinjeske (talk) 05:29, 14 April 2008 (UTC)
 * Beacause it's easy probably, and because a creation of CERN, located in Romandy, was called Worl Wide Web intead of Réseau Mondial or Toile Mondiale possibly. — Preceding unsigned comment added by 177.4.62.112 (talk) 03:10, 22 August 2012 (UTC)

APL ?
Surely APL should be in this list? Porjes (talk)June 3, 2005

'Created in a different language'
the 'created in a diffrent language' category, I've heard of one such language based on Russian, I forgot the name, nor did I have any reliable info.

Reported 'Translated languages'
in the 'translated ' category:
 * I've heard of a version of WISDOM-prolog from the Weizmann-Institude-of-Science-Department-Of-Mathematics, with hebrew keywords, directed at school-children.
 * I've seen a korean version of H-forth

Punctuation as language?
That's an interesting question: does punctuation count as natural language?
 * No, it's just part of a natural language. 81.101.101.229 09:44, 20 May 2006 (UTC)

Category:Programming languages
I noticed a contributor has removed this article from Category:Programming languages. How come? IMO that category is most suitable here, in order to inform readers of the category page that such a concept as non-English prog.languages actually exists. It's not enough to link to this article from Programming language. Contributor, please give a rationale for the category removal. --Wernher 14:52, 15 Aug 2004 (UTC)
 * Hi, Wernher. The way it is now, all items in the Category:Prog langs are indeed prog langs, and the category serves as dynamic list (without the problems of synchronization that the alphabetical list article has). If you take a look at the Subcategories, you'll see that by their own nature, they give rise to lists of programming languages (say, the LISP subcategory -> list of Lisp-related prog langs, and so on). Perhaps we should make an attempt to standardize on the subcategory naming convention, though. The other possible way to use the Category/subcategory hierarchy would be to use the subcategories to actually hold the links to their languages, rather than the Prog Lang category; but this approach has several disadvantages: languages could end up in both the category and subcategory, and there would be no equivalent to the current de facto alphabetical list produced by the category (in fact, if we stick to a consistent interpretation of the category elements, we don't need the List of Prog Langs in Alphabetical Order article any more). Furthermore, if a consensus is reached on how to use the subcategories, we might end up not needing the List of Categorical prog langs article either. One more thing... I did remove HQ9plus as a programming language, but left it as an esoteric one, on the grounds that since it is easier to come up with a valid new esoteric language than with a full-blown language entry, eventually we would end up with a Prog Langs category with an overwhelming majority of esoteric mini-langs over the real langs. ... Anyway, going back to your comment, if anybody is going to take a look at the 'Category:Programming languages' it is actually going to be easier for them to spot 'non-english based languages' page as a subcategory (they come first and are much fewer) and the net effect will still be the same as if it had been listed further down. Please let me know what you think, wish you a good day danakil
 * Hi, and thanks for the quick and enlightening answer to my query. As per your suggestion I have now put the article into the N-E-b.p.l. category (I hadn't discovered its existence when posting my q above, sorry). As you'll notice, I've used the category sorting feature to place the article first on the page, to highlight it as the defining article of the category. One might also link to it in the cat intro, but I think including it in the category as such is appropriate, as that helps readers who are surfing to the article without being aware of the category to become so. A good day to you too. :-) --Wernher 16:05, 15 Aug 2004 (UTC)
 * You're welcome, Wernher, and I'm glad we have consensus. Your comment regarding the defining article of the category left me thinking... Have you considered the fact that the 'Non-English-based programming languages' article is really an article about a category of programming languages... in which case, wouldn't it actually make sense to have the article BE the category (i.e., have all the text in the "article" moved to the category article) and still keep 'Non-English-based programming languages' as a REDIRECT to 'Category:Non-English-based programming languages'... a nice side effect of this move would be that the actual list of neb prog langs would be automatically and dynamically produced... removing the need for that 'known neb prog langs' subsection on the current article. Cheers danakil

EnglishPython
This is probably not quite the right place for it, but oh well. There is a stub on EnglishPython at Python. Unfortunately my Chinese is not good enough to translate it (without a few spare hours).

Also... from zh:Category: English programming language (translation: Chinese programming languages), it looks like these may be worth mentioning: pfctdayelise 08:22, 1 November 2005 (UTC)
 * PerlYuYan
 * Bing Zhengzheng (based on C++)
 * Easy language E-yu-yan - couldn't find any info about this in Chinese, but it certainly gets a tonne of Google hits. perhaps it was natively written in English?

 * Thanks! [see also] —Wiki Wikardo 18:16, 5 October 2012 (UTC)

Non-english assembly langs relevant?
I know of some Norwegian-made minicomputers of the 1960s and 70s whose assembler opcode mnemonics I am reasonably sure were abbreviations of Norwegian-language commands. Would those assembly languages be relevant for listing in this article? After all, they too are programming languages ... --Wernher 08:35, 22 November 2005 (UTC)
 * Absolutely! Awesome if someone could dig up some more inf0z on that. —Wiki Wikardo 20:07, 4 October 2012 (UTC)

Transparent two-way translation?
It would seem that for the restricted domain of a given programming language, it is a totally solvable problem to make an editor that would transparently substitute keywords so that the file was saved in, say, vanilla Python (or whatever your favorite language is) but was edited transparently with native keywords. Variable and function names that clashed with keywords on either side could be escaped by some simple (alpha-only) convention on the other side. This would be a great boon, particularly to educators in other languages - rudimentary if-then-else English can be a job requirement for pro programmers, but not so much for elementary and middle school pre-programming classes.

Obviously, existing codebase would not be translated - just the basic keywords of the language. A right-click facility could show the original keyword in case you needed to search documentation or whatever.

I know that, for instance, MS Excel does a very rudimentary trick like this - if I open an excel document created in English with my Spanish excel, I get functions like PROMEDIO(A2:A9) rather than AVERAGE(A2:A9). But does anyone know of any project to do this to a real programming language? The great thing is, if you made it a plugin to a simple code editor (there are many - such as NotePad++) it would be usable for any prog.language (including languagelike things like CSS or HTML).--Homunq 20:58, 8 May 2007 (UTC)
 * A bug report asking for this feature in bluefish (text editor):

"Mama" vs. "Yiddishe Mama"
Both redirect to the same product and it is said specifically that Mama has an Yiddish version - why split? —Preceding unsigned comment added by 79.182.134.185 (talk) 16:53, 3 July 2010 (UTC)
 * Fixed. —Wiki Wikardo 18:16, 5 October 2012 (UTC)

Title of article
"Non-English-based programming languages" infers that other programming languages are somehow based on the structure of English. This is more into the area of NLP. Isn't there a better way to put it to say that the keywords come from English, but that it has nothing to do with the English language. —Preceding unsigned comment added by 202.158.218.252 (talk) 02:53, 8 February 2011 (UTC)

Binary?
Should Binary be mentioned somewhere? - Kylelovesyou (talk) 00:03, 19 December 2012 (UTC)
 * I think not. Binary is a computer language. But somebody should mention no programmer worth ones salt never uses a language that is localized, since it means there is little to no examples, libraries, updates etc available compared to internationally used programming languages, which are in English. Even a spreadsheet program using localized expressions is painful, and not only to guest stars from abroad, but for locals who try to google for syntax. Believe me, I just experienced it. Just think how difficult it is if your bash suddenly starts to obey only French commands, even if you do speak native French, 8 in Binary is 1000. --84.250.122.35 (talk) 17:07, 29 December 2015 (UTC)

Logo
I used to learn Logo as Bulgarian language based programming language, but the book was in Russian. I still remember the command "left", it's equivalent is "наляво".

ABAB
Could we consider SAP ABAB as being German derived? Significant portions of the language derive keywords from German Abbreviations. — Preceding unsigned comment added by 109.81.210.112 (talk) 20:00, 1 April 2020 (UTC)

Broken Links
Hindi Programming Language – A Hindi programming language for the .NET Framework.[17] <- ref 17 is a broken link — Preceding unsigned comment added by 117.195.156.67 (talk) 15:19, 24 November 2016 (UTC)

mixing languages
Had written transpiler in the past for educational software (MachineLab) that would convert English/Greek Logo to PascalScript and Greek symbols to Greeklish (English-char-based) ones for PascalScript to not reject them. Not sure if such a thing is called a English programming language.

Also in E-Slate Logo (opensource based on TurtleTracks Logo) had implemented support for both Greek (and any other language translations via Java resourcebundles) and English Logo commands in a way where you could even mix them in a program. Also allowed non-English names (via Unicode strings). Not sure if that approach either is a non-English programming language (since it also supports English and mixing non-English with English). E-Slate components supported multiple languages too in their Logo commands via the same Java resourcebundle-based mechanism — Preceding unsigned comment added by 2A02:2149:886C:6400:A5ED:873F:50C3:13A7 (talk) 23:58, 15 July 2017 (UTC)

Merger proposal (List of Chinese programming languages)
I propose List of Chinese programming languages be merged into this article. Chinese programming languages are in the scope of this article, and there aren't so many of them that they need to be in their own article. It would also help to only have one place where this information is displayed. Enterprisey (talk!) 20:17, 4 August 2018 (UTC)
 * With no objections for over a month, doing the merge now. Enterprisey (talk!) 06:24, 12 September 2018 (UTC)

Inclusion criteria
The majority of the languages listed here seem to be non-notable proof-of-concept languages that have only been mentioned in self-published sources by their authors. Even many of the ones that have Wikipedia articles don't seem to have been mentioned in reliable sources at all, such as Ezhil (seemingly no mentions in either English or Tamil sources) and Fjölnir (the only sources that exist are by the author himself).

I don't feel "has been mentioned in a secondary source" is a very strict criteria for inclusion, but we'd probably be left with only a handful of languages. --213.220.68.156 (talk) 21:23, 30 June 2019 (UTC)

Fun English!
I have removed the following entries because I could not verify their existance: --213.220.69.42 (talk) 21:56, 30 June 2019 (UTC)
 * Jeem (C)
 * Bing Zhengzheng (English C++)

Link vs Citation formatting?
I'm a bit confused by the "link" section of the programming languages table. Sometimes they are formatted as citations (useful for their inclusion in the references section), while other times they are manual numbered links (which is liable to failure/inaccuracy when new languages are added).

I'd vote the article take a consistent stance and use citation format for all of them, but would love to hear reasoning behind links instead if folks feel strongly. Darling58 (talk) 11:49, 23 March 2024 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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USS Cod

USS Cod (SS/AGSS/IXSS-224) is a Gato-class submarine, the only vessel of the United States Navy to be named for the cod, an important and very popular food fish of the North Atlantic and North Pacific oceans. She was launched on 21 March 1943, and commissioned on 21 June 1943.

Cod is now a National Historic Landmark, preserved as a museum ship and memorial permanently moored in Cleveland, Ohio, and is open to visitors daily from May to November.

Construction and commissioning
Cod keel was laid down by the Electric Boat Company at Groton, Connecticut, on 21 July 1942. The submarine's four main Cleveland Model 16-248 V16 diesel engines and one Cleveland Model 8-268 auxiliary diesel engine were built by General Motors Cleveland Diesel Engine Division on Cleveland's west side. She was launched on 21 March 1943, sponsored by Mrs. G.M. Mahoney, and commissioned on 21 June 1943 with Commander James C. Dempsey, USN in command. Commander Dempsey had already won fame by sinking the first Japanese destroyer lost in World War II while in command of the submarine USS S-37 (SS-142).

World War II
On 30 August 1943, the American Type C1-B cargo ship SS Alcoa Patriot opened gunfire on Cod in the Caribbean Sea at 12.41667°N, -76.05°W, about 120 nmi north-northwest of Barranquilla, Colombia, and 330 nmi east of the northern entrance to the Panama Canal. Less than three hours later, Alcoa Patrio again sighted Cod and fired on her at 12.03333°N, -76.06667°W, about 105 nmi northwest of Barranquilla and 310 nmi east of the northern entrance to the Panama Canal. Cod suffered no damage or casualties in either incident.

First patrol, 1943 October – 1944 January
Cod arrived in Brisbane, Australia, on 2 October 1943 to prepare for her first war patrol. She sailed from there 20 days later. Penetrating the South China Sea, she contacted few targets, and launched an attack only once, on 29 November, with unobserved results. She returned to Fremantle, Australia, to refit from 16 December 1943 to 11 January 1944.

Second patrol, 1944 February – 1944 March
Cod put to sea for her second war patrol in the South China Sea, off Java, and off Halmahera. On 16 February, she surfaced to sink a sampan by gunfire, and on 23 February, torpedoed a Japanese merchantman. She sent another to the bottom on 27 February, Taisoku Maru (2,473 tons) and two days later attacked a third, only to be forced deep by a concentrated depth charging delivered by a Japanese escort ship.

Third patrol, 1944 March – 1944 June
Refitting at Fremantle again from 13 March – 6 April 1944, Cod sailed to the Sulu Sea and the South China Sea off Luzon for her third war patrol. On 10 May, she attacked a heavily escorted convoy of 32 ships and sank the destroyer Karukaya and cargo merchantman Shohei Maru (7,256 tons) before the escorts drove her down with depth charges. She returned to Fremantle to replenish on 1 June 1944.

Fourth patrol, 1944 July – 1944 August
Cod was put to sea again 3 July on her fourth war patrol. She ranged from the coast of Luzon to Java. She sank the converted net tender, Seiko Maru (708 tons) on 3 August, and a landing craft, LSV-129, on 14 August, and, once more successful, returned to Fremantle 25 August.

Fifth patrol, 1944 September – 1944 November
Cod put to sea on her fifth war patrol 18 September 1944, bound for Philippine waters. She made her first contact, a cargo ship, Tatsushiro Maru (6,886 tons) on 5 October, and sank it. Two days later, she inflicted heavy damage on a tanker. Contacting a large convoy on 25 October, Cod launched several attacks without success. With all her torpedoes expended, she continued to shadow the convoy for another day to report its position. In November she took up a lifeguard station off Luzon, ready to rescue carrier pilots carrying out the series of air strikes on Japanese bases which paved the way for the Battle of Leyte later that month.

Cod returned to Pearl Harbor Naval Base on 20 November 1944, and sailed on to a stateside overhaul at Mare Island Naval Shipyard, returning to Pearl Harbor on 7 March 1945.

Sixth patrol, 1945 March – 1945 May
On 24 March she sailed from Pearl Harbor for the East China Sea on her sixth war patrol. Assigned primarily to lifeguard duty, she used her deck gun to sink a tugboat and its tow on 17 April, rescuing three survivors, and on 24 April launched an attack on a convoy which resulted in the most severe depth charging of her career. The next day, she sent the minesweeper W-41 to the bottom. On 26 April Cod was threatened by a fire in the aft torpedo room, but the ship's crew brought the fire under control and manually launched a torpedo already in its tube before the fire could detonate it. QM2c Lawrence E. Foley and S1c Andrew G. Johnson were washed overboard while freeing the torpedo room hatch. S1c Foley was recovered the next morning, but QM2c Johnson drowned during the night. This was Cod only fatality during World War II.

Seventh patrol, 1945 May – 1946 June
After refitting at Guam between 29 May and 26 June 1945, Cod put out for the Gulf of Siam and the coast of Indo-China on her seventh war patrol. On 9 and 10 July she went to the rescue of a grounded Dutch submarine, O-19, taking its crew on board and destroying the Dutch submarine when it could not be gotten off the reef. This was the only international submarine-to-submarine rescue in history. After returning the Dutch sailors to U.S. Naval Base Subic Bay, between 21 July and 1 August Cod made 20 gunfire attacks on the junks, motor sampans, and barges which were all that remained to supply the Japanese at Singapore. After inspecting each contact to rescue civilian crew, Cod sank it by gunfire and torpedoes, sending to the bottom a total of 23. On 1 August, an enemy plane strafed Cod, forcing her to dive, leaving one of her boarding parties behind. The men were rescued two days later by USS Blenny (SS-324).

When Cod returned to Fremantle 13 August 1945, the crew of O-19 was waiting to throw a party for their rescuers. During that celebration, the two crews learned of the Japanese surrender. To symbolize that moment, another symbol was added to Cod battle flag: the name O-19 under a martini glass.

Cod sailed for home on 31 August. Arriving at Naval Submarine Base New London, on 3 November after a visit to Miami, Florida, Cod sailed to the Philadelphia Navy Yard for a overhaul, returning to New London, Connecticut where she was decommissioned and placed in reserve 22 June 1946.

Post-War service, 1946 June – 1954 June
Cod was mothballed in 1946, Cod was recommissioned in 1951 to participate in NATO anti-submarine training exercises. During the Cold War, Cod traveled to St. John's, Newfoundland, as well as Cuba and South America.

Great Lakes training vessel, 1954 June – 1971 December
Cod was decommissioned in 1954 February and placed in reserve. In 1959 she was towed through the St. Lawrence Seaway to Cleveland, Ohio and was used as a training vessel. The Cod served as a training platform during the reservists' weekend drills. The Cod was reclassified first as an Auxiliary Submarine (AGSS-224) on 1 December 1962, and later as a Unclassified Miscellaneous Submarine (IXSS-224) on 30 June 1971. The Cod was in commission, but classed as "in commission in reserve". On 15 December 1971, the Cod was stricken from the Naval Vessel Register.

Awards and decorations
Cod is credited with sinking more than 12 enemy vessels totaling more than 37,000 tons, and damaging another 36,000 tons of enemy shipping. All seven of her war patrols were considered successful and Cod was awarded seven battle stars for her service in World War II, Cod battleflag and conning tower both carry a cocktail glass above the name O-19 to commemorate the rescue and the party.

Museum ship

A group of Cleveland residents formed the Cleveland Coordinating Committee to Save Cod, Inc., with the goal of preserving the ship as a memorial. In 1976 January, the United States Navy gave guardianship of the submarine to the group. Cod opened for public tours as a floating memorial in May 1976. In 1986, the U.S. Department of the Interior designated Cod a National Historic Landmark. The memorial is open daily between May and November of each year.

Today, Cod is the only World War II United States Navy museum submarine that has not had stairways and doors cut into her pressure hull for public access and is the only World War II Fleet submarine that is still intact and in her wartime configuration. Visitors to the ship use the same vertical ladders and hatches that were used by her crew. The ship's 5-inch deck gun, Mark IV Torpedo Data Computer and all five diesel engines have been restored and are fully operable.

Cleveland can claim partial credit as Cod birthplace, since the submarine's four main diesel engines, and one auxiliary diesel engine were built at the General Motors Cleveland Diesel Engine Division on Cleveland's west side. Cod acquired two General Motors Cleveland Model 16-248 V16 diesel engines that had originally been used aboard another World War II submarine, USS Stingray (SS-186). The engines are held in reserve for parts for the restoration of Cod engines.

The Cod operates an amateur radio station, W8COD, and participates in various amateur radio contests and other events such as Field Day.

On 13 June 2021, Cod departed Cleveland under tow to Donjon Shipbuilding & Repair in Erie, Pennsylvania for dry docking to repair and renew her underwater hull. The last time the Cod was in dry dock for repairs was in 1963 in Lorain, Ohio. Cod was closed to tours for approximately 64 days for a dry dock maintenance program. The goal of the US$1.1 million project, partially funded by a US$395,050 grant from the Save America's Treasures grant program administered by the U.S. Department of the Interior, is to conserve and restore the underwater hull of the submarine. Cod returned to Cleveland on 18 August 2021 to the 1201 North Marginal Road berth that she has occupied since her arrival in Cleveland in 1959.

On 21 June 2023, Cod celebrated its 80th anniversary of commissioning during World War II.

Appearances in popular culture
Cod was subject of the television series The Silent Service and was the main plot for an episode titled The USS Cod's Lost Boarding Party which aired on 30 May 1958 on NBC.

Cod was used for exterior and interior scenes for the Smithsonian Channel war documentary Hell Below to depict USS Tang (SS-306), GS U-99 (1940) and GS U-100 (1940). Filming took place aboard the Cod in 2015. The documentary aired on 17 July 2016.

Cod was the subject of a two-part documentary on the World of Warships YouTube channel titled Naval Legends: USS Cod. The documentary published on 2 and 4 July 2019.

Cod was used for exterior and interior scenes for the Dolph Lundgren motion picture Operation Seawolf to depict World War II German U-Boats. The motion picture released on 7 October 2022.

title: USS Cod


text:
Talk:Zilog Z800

Production
If the Z800 never entered production, then how could it have been used in "MSX Turbo R" computers?? Stan 17:43, 13 Nov 2003 (UTC)

IIRC they were the Hitachi versions, not the "real" Zilog ones. Things are somewhat confused by the fact that both the Z800 and Z8000 were to be released at the same time, MANY sources confuse the two.

 * Hitachi licensed the design then? I know nothing of this period in Zilog history, seems like a curious story. Stan 16:46, 15 Nov 2003 (UTC)

 * Hitachi second sourced the Z80 under licence. They have a history of second sourcing and then improving processors (see for example the 6309). At the time it was normal to have second sources to your products in order to get acceptance. In addition according to http://www.cpushack.com/2010/10/15/zilog-the-first-decade-z80-z8-and-the-z8000/#more-393 people could buy licences to produce and modify Z80 variants - just like ARM today 81.96.49.166 (talk) 21:00, 16 February 2018 (UTC)

However Zilog essentially ignored the Z800 in favour of their 32-bit Z8000 there is definitely a mistake in this sentence: the Z8000 was/is a 16-bit processor, the 32-bit Zilog processor was/is the Z80000. Since I don't know if the 32-bit or the Z8000 is wrong here I did not change anything so far IOOI 01:10, 3 Dec 2003 (UTC)

 * Z8000 is 16bit I think the article means Z80000. The Z8000 is 16bit but not Z80 like 81.96.49.166 (talk) 21:00, 16 February 2018 (UTC)

z280?
Article sounds like Z800 was burried before beeing born. But Z280 article sais that Z800 architecture was re-launched when moved from NMOS to CMOS technology.

If that is true - IMHO Z280 should be mentioned in this areticle as a Z800 spin-off

Disambiguation
I came to this page assuming to find an article about the Z800 3D visor. What about transforming this page into a disambiguation page with the links to Z800 (processor) and Z800 (visor)? -- Devil Master 14:19, 11 Sep 2006 (MET)

Five years
How is it "more than five years had elapsed" between 1985 and 1986? --Pkunk (talk) 19:13, 26 February 2013 (UTC)

 * This seems unclear to me as well. Dave Olsen mentions 'I just got in a new Zilog catalog and found the technical specs for the Z800 chip.' in a document dated 8th Jan 85. I've not got all the catalogues to check but that would be a useful search. Catalogues before that (eg the 1983/1984 Zilog Component Databook) include most of the data you'd expect on the Z800 (instruction set etc). It's also i the 1983 'Microprocessor Applications Reference Book vol2' from Zilog. Tilmann Reh who did only of the first homebrew Z280 platforms also cites 1983 in TCJ #53 (http://oldcomputers.dyndns.org/public/pub/rechner/zilog/z280/Z280_(G)IDE_a_compilation_from_TCJ_pages.pdf)

Something call the Z800 was announced in concept by 1978. See New Scientist 18th May 1978 "Microprocessors don't always work" about the introducing of the classic shift register BIST (built in self test) which includes the lines 'Starting this summer the microprocessor world will take another huge step forward in complexity, with the arrival of devices such as Zilog's Z800 processor -- said to have the power of the larger Digital Equipment Corporation PDP-11/70 minicomputer"

There's a ton of background timeline info in Computer History Museum Oral History Ref X4022.2006(http://archive.computerhistory.org/resources/text/Oral_History/Zilog_Z8000/102658075.05.01.acc.pdf). Faggin talks about the Z800 as a concept and reserving the id for a 'super Z80' so naming the Z8000 as 8000 not 800 and also that the Z800 didn't happen until after he left which would put it 1981+. I think this adds to the confusion because there are discussions and advertising spin about Z800 that clearly are about what became the Z8000.

So I think the timeline is

1978 - Zilog have a Z800 at least enough to be spinning it to the press (but that's the Z8000 prior to Faggin changing the name) (They concentrate on the Z8000/80000) 1980 (end of) Faggin leaves Zilog some point after that they begin the Z800 (as Faggin says it happened after he left and he was CEO so he ought to know...) 1983 - It exists enough to be in a databook and promoted for some products. 1985 - They finally announce it as a product (by then in CMOS) 1986 - They ship it.

At which point the comment would make sense. All very sad because if Zilog had their ducks in order they'd have been in the IBM PC and we'd have had memory protection, virtual memory, cache and multi-processor support in the IBM PC from day one and been able to run real OS's back then.

That would also tie in with the descriptions elsewhere of why many of the bugs never got fixed because they'd have had to import the Z800 design into their current design tools. And also of course by 1986 it's up against not only a well established 80286 which also had memory protection since 1982, and the newfangled 80386 which is 32bit with paged MMU and buried it.

The computer history Z8000 article is well worth reading. It explains much about the state of things in Zilog and where Faggin says they were trying to do too many things and there were management problems.

81.96.49.166 (talk) 21:00, 16 February 2018 (UTC)

And another data point I just found Business Week July 26 1982 in 'A chip waiting to explode: Customers were confounded by the complexity of the 16bit microproccessor chip' says of Zilog 'Late next year, it plans to launch a high-performance, 8-bit microprocessor called the Z800. Industry experts suggest that next year could be too late, but Vonderschmitt argues that "an upgraded 8-bit product will benefit from all the software and all the peripheral circuits that already exist."'

So we have 1982-1986/7 - which sounds about right

81.96.49.166 (talk) 21:19, 16 February 2018 (UTC)

What is EDN?
The article refers to a mysterious "EDN November 27, 1986 p133" instance. Can anybody explain what is this EDN? Pkunk (talk) 18:56, 4 March 2013 (UTC)
 * A magazine. EDN stands for Electronic Design News.   174.25.9.105 (talk) 06:55, 28 October 2015 (UTC)

title: Talk:Zilog Z800


text:
Ford circle

In mathematics, a Ford circle is a circle in the Euclidean plane, in a family of circles that are all tangent to the $$x$$-axis at rational points. For each rational number $$p/q$$, expressed in lowest terms, there is a Ford circle whose center is at the point $$(p/q,1/(2q^2))$$ and whose radius is $$1/(2q^2)$$. It is tangent to the $$x$$-axis at its bottom point, $$(p/q,0)$$. The two Ford circles for rational numbers $$p/q$$ and $$r/s$$ (both in lowest terms) are tangent circles when $$|ps-qr|=1$$ and otherwise these two circles are disjoint.

History
Ford circles are a special case of mutually tangent circles; the base line can be thought of as a circle with infinite radius. Systems of mutually tangent circles were studied by Apollonius of Perga, after whom the problem of Apollonius and the Apollonian gasket are named. In the 17th century René Descartes discovered Descartes' theorem, a relationship between the reciprocals of the radii of mutually tangent circles.

Ford circles also appear in the Sangaku (geometrical puzzles) of Japanese mathematics. A typical problem, which is presented on an 1824 tablet in the Gunma Prefecture, covers the relationship of three touching circles with a common tangent. Given the size of the two outer large circles, what is the size of the small circle between them? The answer is equivalent to a Ford circle:

 * $$\frac{1}{\sqrt{r_\text{middle}}} = \frac{1}{\sqrt{r_\text{left}}} + \frac{1}{\sqrt{r_\text{right}}}.$$

Ford circles are named after the American mathematician Lester R. Ford, Sr., who wrote about them in 1938.

Properties
The Ford circle associated with the fraction $$p/q$$ is denoted by $$C[p/q]$$ or $$C[p,q].$$ There is a Ford circle associated with every rational number. In addition, the line $$y=1$$ is counted as a Ford circle – it can be thought of as the Ford circle associated with infinity, which is the case $$p=1,q=0.$$

Two different Ford circles are either disjoint or tangent to one another. No two interiors of Ford circles intersect, even though there is a Ford circle tangent to the x-axis at each point on it with rational coordinates. If $$p/q$$ is between 0 and 1, the Ford circles that are tangent to $$C[p/q]$$ can be described variously as
 * 1) the circles $$C[r/s]$$ where $$|p s-q r|=1,$$
 * 2) the circles associated with the fractions $$r/s$$ that are the neighbors of $$p/q$$ in some Farey sequence, or
 * 3) the circles $$C[r/s]$$ where $$r/s$$ is the next larger or the next smaller ancestor to $$p/q$$ in the Stern–Brocot tree or where $$p/q$$ is the next larger or next smaller ancestor to $$r/s$$.

If $$C[p/q]$$ and $$C[r/s]$$ are two tangent Ford circles, then the circle through $$(p/q,0)$$ and $$(r/s,0)$$ (the x-coordinates of the centers of the Ford circles) and that is perpendicular to the $$x$$-axis (whose center is on the x-axis) also passes through the point where the two circles are tangent to one another.

The centers of the Ford circles constitute a discrete (and hence countable) subset of the plane, whose closure is the real axis - an uncountable set.

Ford circles can also be thought of as curves in the complex plane. The modular group of transformations of the complex plane maps Ford circles to other Ford circles.

Ford circles are a sub-set of the circles in the Apollonian gasket generated by the lines $$y=0$$ and $$y=1$$ and the circle $$C[0/1].$$

By interpreting the upper half of the complex plane as a model of the hyperbolic plane (the Poincaré half-plane model), Ford circles can be interpreted as horocycles. In hyperbolic geometry any two horocycles are congruent. When these horocycles are circumscribed by apeirogons they tile the hyperbolic plane with an order-3 apeirogonal tiling.

Total area of Ford circles
There is a link between the area of Ford circles, Euler's totient function $$\varphi,$$ the Riemann zeta function $$\zeta,$$ and Apéry's constant $$\zeta(3).$$ As no two Ford circles intersect, it follows immediately that the total area of the Ford circles

 * $$\left\{ C[p,q]: 0 < \frac{p}{q} \le 1 \right\}$$

is less than 1. In fact the total area of these Ford circles is given by a convergent sum, which can be evaluated. From the definition, the area is

 * $$ A = \sum_{q\ge 1} \sum_{ (p, q)=1 \atop 1 \le p < q }\pi \left( \frac{1}{2 q^2} \right)^2.$$

Simplifying this expression gives

 * $$ A = \frac{\pi}{4} \sum_{q\ge 1} \frac{1}{q^4}

\sum_{ (p, q)=1 \atop 1 \le p < q } 1 = \frac{\pi}{4} \sum_{q\ge 1} \frac{\varphi(q)}{q^4} = \frac{\pi}{4} \frac{\zeta(3)}{\zeta(4)},$$

where the last equality reflects the Dirichlet generating function for Euler's totient function $$\varphi(q).$$ Since $$\zeta(4)=\pi^4/90,$$ this finally becomes

 * $$ A = \frac{45}{2} \frac{\zeta(3)}{\pi^3}\approx 0.872284041.$$

Note that as a matter of convention, the previous calculations excluded the circle of radius $$\frac{1}{2}$$ corresponding to the fraction $$\frac{0}{1}$$. It includes the complete circle for $$\frac{1}{1}$$, half of which lies outside the unit interval, hence the sum is still the fraction of the unit square covered by Ford circles.

Ford spheres (3D)
The concept of Ford circles can be generalized from the rational numbers to the Gaussian rationals, giving Ford spheres. In this construction, the complex numbers are embedded as a plane in a three-dimensional Euclidean space, and for each Gaussian rational point in this plane one constructs a sphere tangent to the plane at that point. For a Gaussian rational represented in lowest terms as $$p/q$$, the diameter of this sphere should be $$1/2q\bar q$$ where $$\bar q$$ represents the complex conjugate of $$q$$. The resulting spheres are tangent for pairs of Gaussian rationals $$P/Q$$ and $$p/q$$ with $$|Pq-pQ|=1$$, and otherwise they do not intersect each other.

title: Ford circle


text:
Domain hijacking

Domain hijacking or domain theft is the act of changing the registration of a domain name without the permission of its original registrant, or by abuse of privileges on domain hosting and registrar software systems.

This can be devastating to the original domain name holder, not only financially as they may have derived commercial income from a website hosted at the domain or conducted business through that domain's e-mail accounts, but also in terms of readership and/or audience for non-profit or artistic web addresses. After a successful hijacking, the hijacker can use the domain name to facilitate other illegal activity such as phishing, where a website is replaced by an identical website that records private information such as log-in passwords, spam, or may distribute malware from the perceived "trusted" domain.

Description
Domain hijacking can be done in several ways, generally by unauthorized access to, or exploiting a vulnerability in the domain name registrar's system, through social engineering, or getting into the domain owner's email account that is associated with the domain name registration.

A frequent tactic used by domain hijackers is to use acquired personal information about the actual domain owner to impersonate them and persuade the domain registrar to modify the registration information and/or transfer the domain to another registrar, a form of identity theft. Once this has been done, the hijacker has full control of the domain and can use it or sell it to a third party.

Other methods include email vulnerability, vulnerability at the domain-registration level, keyloggers, and phishing sites.

Responses to discovered hijackings vary; sometimes the registration information can be returned to its original state by the current registrar, but this may be more difficult if the domain name was transferred to another registrar, particularly if that registrar resides in another country. If the stolen domain name has been transferred to another registrar, the losing registrar may invoke ICANN's Registrar Transfer Dispute Resolution Policy to seek the return of the domain.

In some cases the losing registrar for the domain name is not able to regain control over the domain, and the domain name owner may need to pursue legal action to obtain the court ordered return of the domain. In some jurisdictions, police may arrest cybercriminals involved, or prosecutors may file indictments.

Although the legal status of domain hijacking was formerly thought to be unclear, certain U.S. federal courts in particular have begun to accept causes of action seeking the return of stolen domain names. Domain hijacking is analogous with theft, in that the original owner is deprived of the benefits of the domain, but theft traditionally relates to concrete goods such as jewelry and electronics, whereas domain name ownership is stored only in the digital state of the domain name registry, a network of computers. For this reason, court actions seeking the recovery of stolen domain names are most frequently filed in the location of the relevant domain registry. In some cases, victims have pursued recovery of stolen domain names through ICANN's (Uniform Domain Name Dispute Resolution Policy (UDRP), but a number of UDRP panels have ruled that the policy is not appropriate for cases involving domain theft. Additionally, police may arrest cybercriminals involved.

Notable cases

 * During the original "dot com boom", there was extensive media coverage of the hijacking of "sex.com".
 * Basketball player Mark Madsen unknowingly bought a "stolen" (or hijacked) URL by way of eBay auctions.
 * In 2015 Lenovo's website and Google's main search page for Vietnam were briefly hijacked.
 * In early 2021, Perl's domain was briefly hijacked, causing a relatively major issue with CPAN.

Prevention
ICANN imposes a 60-day waiting period between a change in registration information and a transfer to another registrar. This is intended to make domain hijacking more difficult, since a transferred domain is much more difficult to reclaim, and it is more likely that the original registrant will discover the change in that period and alert the registrar. Extensible Provisioning Protocol is used for many TLD registries, and uses an authorization code issued exclusively to the domain registrant as a security measure to prevent unauthorized transfers.

RFC’s

 * - Generic Registry-Registrar Protocol Requirements
 * - Guidelines for Extending EPP
 * - Domain Registry Grace Period Mapping (e.g. Add Grace Period, Redemption Grace Period)
 * - Using EPP for ENUM addresses
 * - Domain Name System (DNS) Security Extensions Mapping for the Extensible Provisioning Protocol (EPP) (obsoletes, DNSSEC)
 * - Extensible Provisioning Protocol (EPP) (obsoletes, which obsoleted )
 * - Extensible Provisioning Protocol (EPP) Domain Name Mapping (obsoletes )
 * - Extensible Provisioning Protocol (EPP) Host Mapping (obsoletes )
 * - Extensible Provisioning Protocol (EPP) Contact Mapping (obsoletes )
 * - Extensible Provisioning Protocol (EPP) Transport over TCP (obsoletes )

title: Domain hijacking


text:
Index of biochemistry articles

Biochemistry is the study of the chemical processes in living organisms. It deals with the structure and function of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules.

Articles related to biochemistry include:

0–9
2-amino-5-phosphonovalerate - 3' end - 5' end

A
ABC-Transporter Genes - abl gene - acetic acid - acetyl CoA - acetylcholine - acetylcysteine - acid - acidic fibroblast growth factor - acrosin - actin - action potential - activation energy - active site - active transport - adenosine - adenosine diphosphate (ADP) - adenosine monophosphate (AMP) - adenosine triphosphate (ATP) - adenovirus - adrenergic receptor - adrenodoxin - aequorin - aerobic respiration - agonist - alanine - albumin - alcohol - alcoholic fermentation - alicyclic compound - aliphatic compound - alkali - allosteric site - allostery - allotrope - allotropy - alpha adrenergic receptor - alpha helix - alpha-1 adrenergic receptor - alpha-2 adrenergic receptor - alpha-beta T-cell antigen receptor - alpha-fetoprotein - alpha-globulin - alpha-macroglobulin - alpha-MSH - Ames test - amide - amine - amino - amino acid - amino acid receptor - amino acid sequence - amino acid sequence homology - aminobutyric acid - ammonia - AMPA receptor - amyloid - anabolism - anaerobic respiration - analytical chemistry - androgen receptor - angiotensin - angiotensin II - angiotensin receptor - ankyrin - annexin II - antibiotic - antibody - apoenzyme - apolipoprotein - apoptosis - aquaporin - archaea - arginine - argipressin - aromatic amine - aromatic compound - arrestin - Arrhenius equation - aryl hydrocarbon receptor - asparagine - aspartic acid - atom - atomic absorption spectroscopy - atomic mass - atomic mass unit - atomic nucleus - atomic number - atomic orbital - atomic radius - Atomic weight - ATP synthase - ATPase - atrial natriuretic factor - atrial natriuretic factor receptor - Avogadro constant - axon

B
B cell - bacteria - bacterial conjugation - bacterial outer membrane protein - bacterial protein - bacteriorhodopsin - base (chemistry) - base pair - base sequence - basic fibroblast growth factor - Bcl-2 - bcr-abl fusion protein - benzene - benzene ring - beta-2 microglobulin - beta adrenergic receptor - beta sheet - beta-1 adrenergic receptor - beta-2 adrenergic receptor - beta-thromboglobulin - bioaccumulation - biochemistry - biodiversity - bioethics - biogenic amine receptor - bioinformatics - biological membrane - biologist - biology - biomechanics - biomedical model - biomolecule - biophysics - biopolymer - biosalinity - biotechnology - BLAST - blood proteins - boiling point - Boltzmann distribution - Boltzmann principle - bombesin - bombesin receptor - bone morphogenetic protein - bradykinin - bradykinin receptor - BRCA1 - buffer solution

C
C-terminus - C4 photosynthesis - cadherin - calbindin -calcitonin - calcitonin gene-related peptide - calcitonin gene-related peptide receptor - calcitonin receptor - calcitriol receptor - calcium channel - calcium signaling - calcium-binding protein - calmodulin - calmodulin-binding protein - Calvin cycle - CAM photosynthesis - CAM plants - cancer - capsid - carbohydrate - carbon - carbon fixation - carboxylic acid - carcinoembryonic antigen - carrier - carrier protein - CAS registry number - casein - catabolism - catalyst - catalytic domain - CCR5 receptor - CD4 antigen - CD45 antigen - CD95 antigen - CDC28 protein kinase - cell - cell adhesion molecule - cell biology - cell cycle protein - cell membrane - cell membrane transport - cell nucleus - cell surface receptor - cellular respiration - cellulose - centriole - centromere - centrosome - chaperone - chelation - chemical biology - chemical bond - chemical compound - conformation - chemical element - chemical equilibrium - chemical formula - chemical nomenclature - chemical property - chemical reaction - chemical series - chemical thermodynamics - cheminformatics - chemiosmosis - chemiosmotic hypothesis - chemiosmotic potential - chemist - chemistry - chemistry basic topics - chemotroph - chemokine receptor - chemoreceptor - chiasma - chimera (protein) - chimeric protein - chirality - chloride channel - chlorophyll - chloroplast - chloroplast membrane - cholecystokinin receptor - cholesterine - cholinergic receptor - chorionic gonadotropin - chromatid - chromatin - ciclosporin - chromatography - chromosomal crossover - chromosome - chromosome walking - cilium - circular dichroism - cis face - citric acid - citric acid cycle - cladistics - cloning - coenzyme - cofactor (biochemistry) - colchicine - collagen - colloid - colony-stimulating factor - colony stimulating factor 1 receptor - colorimeter - comparative biochemistry - competitive inhibition - complement 3A - complement 5A - complement factor B - complement membrane attack complex - complement receptor - complex - computational biology - computational chemistry - computational genomics - concanavalin A - concentration - concentration gradient - consensus sequence - conserved sequence - cooperative - cooperative binding - cooperativity - cooperativity cellular respiration - corticotropin - corticotropin receptor - corticotropin-releasing hormone - corticotropin-releasing hormone receptor - cotransport metabolism - covalent bond - covalent radius - CpG island - cristae - cryptobiology - crystal structure - crystallography - cuticula - CXCR4 receptor - cyclic AMP receptor - cyclic AMP receptor protein - cyclic AMP-responsive DNA-binding protein - cyclic electron flow - cyclic nucleotide - cyclic peptide - cyclin - cyclin A - cyclin B - cyclin E - cyclin-dependent kinase - cycloleucine - cyclosporin - cyclosporine - cystatin - cysteine - cystic fibrosis transmembrane conductance regulator - cytochrome B - cytochrome C - cytochrome P-450 - cytochrome P-450 CYP1A1 - cytochrome C oxidase - cytokine receptor - cytoplasm - cytoplasmic and nuclear receptor - cytosine - cytoskeletal protein - cytoskeleton - cytosol - cytotoxic T cell

D
dactinomycin - decarboxylation reaction - delta opioid receptor - denaturation (biochemistry) - dendrite - dendritic cell - dendritic spine - deoxyribonucleoprotein - deoxyribose - desmopressin - deuterium - developmental biology - dialysis (chemical) - diffusion - dimer - dinucleotide repeat - diploid - disaccharide - dissociation constant - disulfide bond - disulfide bridge - DNA - DNA fragmentation - DNA replication - DNA sequence - DNA topology - DNA transposable element - DNA virus - DNA-binding protein - dopamine D1 receptor - dopamine D2 receptor - dopamine receptor - double helix - Drosophila - drugs - dynorphin

E
eIF-2 - eIF-2 kinase - electrochemical potential - electron - electron capture - electron configuration - electron microscopy - electron shell - electron transport chain - electron volt - electronegativity - electrophile - electrophoresis - electrophysiology - element - element symbol - ELISA - ELISPOT - embryo - embryonal development - emulsion - endergonic reaction - endodermis - endomembrane system - endoplasmic reticulum - endothelin receptor - endothelin-1 - energy decomposition cycles - energy level - enhancer - enkephalin - enthalpy - entomology - entropy - env gene product - environmental chemistry - enzyme - epidermal growth factor - epidermal growth factor receptor - epidiorite - epigenetics - epinephrine - equine gonadotropin - erbA gene - erbB gene - erbB-2 gene - erbB-2 receptor - erythropoietin - erythropoietin receptor - essential amino acid - ester - estradiol receptor - estrogen receptor - ethanol - ether - eukaryote - evolution - evolutionary biology - evolutionary developmental biology - evolutionary tree - excretion - exergonic reaction - exon - extracellular matrix protein - eye proteins

F
fab immunoglobulin - facilitated diffusion - factor VIII - FADH - FADH2 - Fat - Fatty acid - fc immunoglobulin - fc receptor - feedback inhibition - fermentation - fetal protein - fibroblast growth factor - fibroblast growth factor receptor - fibronectin - Fick's law of diffusion - Filtration - fitness (biology) - fitness landscape - flagellum - flavin adenine dinucleotide - flavine - flavoprotein - fluid mosaic model - fms gene - Formaldehyde - fos gene - free energy - freezing point - FSH receptor - functional group - fungal protein - fungi - fusion oncogene protein

G
G protein - G protein-coupled receptor - G3P - GABA - GABA receptor - GABA-A receptor - gag-onc fusion protein - galanin - gamete - gamma-chain immunoglobulin - gamma-delta T-cell antigen receptor - gastrin - gastrointestinal hormone receptor - gastrula - gel electrophoresis - gene - gene expression - gene pool - gene regulatory network - genetic carrier - genetic code - genetic drift - genetic engineering - genetic fingerprint - genetic recombination - genetics - genome - genomics - genotype - glial fibrillary acidic protein - globin - glucagon - glucagon receptor - glucocorticoid receptor - glucose - glutamate - glutamate receptor - glutamic acid - glutamine - glycerine - glycine - glycine receptor - glycolipid - glycolysis - glycoprotein - gonadorelin - gradient - granulocyte colony-stimulating factor - granulocyte colony-stimulating factor receptor - granulocyte-macrophage colony-stimulating factor - granulocyte-macrophage colony-stimulating factor receptor - granzyme - growth factor receptor - GTP-binding protein - GTPase

H
hair cell - half-life - halobacteria - halotolerance - haploid - heat of fusion - heat of vaporization - heat shock protein - Hsp70 (70 kDa heat shock proteins) - Hsp90 (90 kDa heat shock proteins) - heavy-chain immunoglobulin - Hela cell - helminth protein - helper T cell - hemopexin - hemoglobin - herpes simplex virus protein vmw65 - heterocyclic compound - heterotroph - heterozygote - Hfr cell - Hill reaction - His tag - histamine H1 receptor - histamine H2 receptor - histamine receptor - histidine - histone - history of science and technology - HIV receptor - holoenzyme - homeobox - homeodomain protein - homology - homoserine - homozygote - homunculus - hormone - housekeeping gene - Human Genome Project - hybridization - hydrocarbon - hydrogen - hydrogen bond - hydrogenation - hydrogen-deuterium exchange - hydrolysis - hydrolytic enzyme - hydrophilic - hydrophobe - hydrophobic - hydrophobicity analysis - hydroxyl

I
IgA - IgE receptor - IGF type 1 receptor - IGF type 2 receptor - IgG - IgM - immediate-early protein - immune cell - immune system - immunoglobulin - immunoglobulin joining region - immunoglobulin variable region - immunologic receptor - immunology - In vivo - infrared spectroscopy - inhibin - inhibitor - inhibitory gi G-protein - Inorganic chemistry - insect protein - Insulin - insulin receptor - insulin-like growth factor I - Integral membrane protein - intein - intercellular adhesion molecule-1 - interferon receptor - interferon type I - interferon type II - interferon-alpha - interferon-beta - interleukin receptor - interleukin-1 receptor - interleukin-2 receptor - interleukin-3 - interleukin-3 receptor - intermediate filament - intermediate filament protein - intermembrane space - Intermolecular force - International Union of Pure and Applied Chemistry (IUPAC) - interphase - intracisternal A-particle gene - Intramolecular force - intron - Inverse agonist - invertebrate peptide receptor - invertebrate photoreceptor - Ion channel - ion channel gating - Ionic bond - ionization potential - iron–sulfur protein - isoenzyme - isoleucine - Isomer - Isothermal titration calorimeter - Isotopic tracer

J
junk DNA

K
kainic acid receptor - kallidin - kappa opioid receptor - kappa-chain immunoglobulin - karyoplasm - karyotype - kelvin - keratin - kinase - kinesin - kinetic energy - kinetic exclusion assay - kinetics - knock-out mouse - Krebs cycle

L
lactalbumin - lactic acid - lactic acid autotroph - lactic fermentation - lagging strand - laminin - LDL receptor - Le Chatelier's principle - lectin - leucine - leucine-2-alanine enkephalin - leukotriene B4 receptor - LH - LH receptor - LHRH receptor - life - life form - ligand - light reactions - Lineweaver-Burk diagram - lipase - lipid - lipid anchored protein - lipid bilayer - lipoprotein - liquid - list of compounds - list of gene families - locus - luminescent protein - lymphocyte homing receptor - lysine - lysis - lysis buffer - lysozyme - lytic cycle

M
macroevolution - macromolecular system - macromolecule - macrophage colony-stimulating factor - major histocompatibility complex - Malpighi body - Malpighi layer - marine biology - maslinic acid - mass spectrometer - maturation-promoting factor - mechanoreceptor - medicine - meiosis - melting point - membrane glycoprotein - membrane protein - membrane topology - membrane transport - memory B cell - memory T cell - Mendelian inheritance - metabolic pathway - metabolism - metabotropic glutamate receptor - metalloprotein - metaphase - metazoa - methionine - micelle - Michaelis-Menten kinetics - microbe - microbiology - microevolution - microfilament - microfilament protein - microsatellite - microscope - microtiter plate - microtubule-associated protein - mineralocorticoid receptor - minisatellite - mitochondrial membrane - mitochondrion - mitogen receptor - mitosis - mitotic spindle - mixture - modern evolutionary synthesis - molar volume - mole (unit) - molecular biology - molecular chaperone - molecular dynamics - molecular engineering - molecular evolution - molecular mechanics - molecular modelling - molecular orbital - molecular phylogeny - molecular sequence data - molecule - monoamine - monoclonal antibody - monomer - monosaccharide - monosaccharide transport protein - morphogenesis - morphogenetic field - mos gene - Mössbauer spectroscopy - MRI - MSH - mu opioid receptor - mu-chain immunoglobulin - mucin - Muller's ratchet - multiresistance - muscarinic receptor - muscle - muscle protein - mutagen - mutation - myc gene - mycology - myelin basic protein - myeloma protein - myosin

N
N-formylmethionine - N-formylmethionine leucyl-phenylalanine - N-methyl-D-aspartate receptor - N-methylaspartate - N-terminus - NADH - NADPH - NaKATPase - native state - nef gene product - neoplasm protein - Nernst equation - nerve - nerve growth factor - nerve growth factor receptor - nerve tissue protein - nerve tissue protein S 100 - nervous system - neurobiology - neurofilament protein - neurokinin A - neurokinin K - neurokinin-1 receptor - neurokinin-2 receptor - neuron - neuronal cell adhesion molecule - neuropeptide - neuropeptide receptor - neuropeptide Y - neuropeptide Y receptor - neuroscience - neurotensin - neurotensin receptor - neurotransmitter - neurotransmitter receptor - neutral theory of molecular evolution - neutron - neutron activation analysis - NF-kappa B - nicotinic receptor - nitrogen - nitroglycerine - Nobel Prize in Chemistry - non-competitive inhibition - nuclear lamina - nuclear localization signal - nuclear magnetic resonance - NMR - nuclear protein - nucleic acid - nucleic acid regulatory sequence - nucleic acid repetitive sequence - nucleic acid sequence homology - nucleon - nucleophile - nucleoside - nucleosome - nucleotide - nutrition

O
octreotide - odorant receptor - olfaction - olfactory receptor neuron - oligopeptide - oncogene - oncogene protein - oncogene proteins V-abl - oncogenic retroviridae protein - open reading frame - opioid receptor - opsin - optical isomerism - organ (anatomy) - organelle - organic chemistry - organic compound - organic nomenclature - organic reaction - organism - osmosis - osteocalcin - outer hair cell - outline of biochemical techniques - ovalbumin - oxidation - oxidation number - oxidation state - oxidative decarboxylation - oxidative phosphorylation - oxygen - oxytocin - oxytocin receptor

P
P42 MAP kinase -p53 - pancreatic polypeptide - parathyroid hormone receptor - partial pressure - passive transport - Pauling scale - PCR - peptide - peptide bond - peptide elongation factor - peptide elongation factor tu - peptide fragment - peptide initiation factor - peptide receptor - peptide termination factor - peripheral membrane protein - pesticide - pH - phage display - pharmaceutical - pharmacist - pharmacology - phenol - phenotype - phenyl group - phenylalanine - Philadelphia chromosome - phospholipid - phospholipid bilayer - phosphopeptide - phosphoprotein - phosphorus - phosphorylation - phosphoserine - phosphothreonine - phosphotyrosine - photobiology - photolysis - photophosphorylation - photoreceptor - photorespiration - photosynthesis - photosystem I - photosystem II - phototransduction - phylogenetics - phylogeny - physical chemistry - physiology - phytohaemagglutinin - pituitary hormone receptor - pituitary hormone-regulating hormone receptor - plant protein - plasma membrane - plasmid - plasmin - plasminogen - platelet glycoprotein GPIb-IX complex - platelet membrane glycoprotein - platelet-derived growth factor - platelet-derived growth factor receptor - polymer - polymerase chain reaction - polymerization - polymyxin - polymyxin B - polyomavirus transforming antigen - polypeptide - polysaccharide - porphyrin - Posttranslational modification - potassium - potassium channel - potential energy - pregnancy proteins - primary nutritional groups - primary structure - primer - prion - progesterone receptor - prokaryote - prolactin - prolactin receptor - proline - promoter - prostaglandin e receptor - prostaglandin receptor - protein - protein biosynthesis - Protein Data Bank - protein design - protein expression - protein folding - protein isoform - protein nuclear magnetic resonance spectroscopy - protein P16 - protein P34cdc2 - protein precursor - protein structure prediction - protein subunit - protein synthesis - protein targeting - protein translocation - protein-tyrosine kinase - protein-tyrosine-phosphatase - proteinoid - proteomics - protirelin - proto-oncogene - proto-oncogene proteins - proto-oncogene protein C-kit - proto-oncogene proteins c-abl - proto-oncogene proteins c-bcl-2 - Proto-oncogene proteins c-fos - proto-oncogene proteins c-jun - proto-oncogene proteins c-mo - proto-oncogene proteins c-myc - proto-oncogene proteins c-raf - proton - proton pump - protozoan proteins - purine - purinergic P1 receptor - purinergic P2 receptor - purinergic receptor - pyridine - pyrimidine - pyruvate - pyruvate oxidation

Q
quantum chemistry - quaternary structure

R
radioisotope - radioisotopic labelling - Raman spectroscopy - random coil - Ras gene - Ras protein - reading frame - receptor (biochemistry) - receptor antagonist - receptor protein-tyrosine kinase - recombinant fusion protein - recombinant interferon-gamma - recombinant protein - recombination - redox - redox reaction - redox system - reflux - replication origin - replicon - repressor - repressor protein - respiration (physiology) - restriction enzyme - retinoblastoma protein - retinoic acid receptor - retinol-binding protein - retroelement - retroviridae protein - retrovirus - Reverse transcriptase - RFLP - rho factor - rhodopsin - ribonucleoprotein - ribose - ribosomal protein - ribosomal protein S6 kinase - ribosome - RNA - RNA virus - RNA-binding protein - RNA-directed DNA polymerase - rod outer segment - rough ER

S
sarcoplasmic reticulum - satellite DNA - scientific notation - SDS-PAGE - second messenger - second messenger system - secondary structure - secretin - selectin - sensory receptor - sequence (biology) - sequence homology - sequence motif - sequencing - serine - serotonin - serotonin receptor - serpin - sexual reproduction - SH3 domain - SI - sigma factor - signal peptide - signal recognition particle - signal sequence - signal transduction - sincalide - skeleton - skin - smooth ER - sodium channel - sodium-hydrogen antiporter - soluble - solution - solvation - solvent - somatomedin - somatomedin receptor - somatostatin - somatostatin receptor - somatotropin - somatotropin receptor - somatotropin-releasing hormone - somatropin - sp1 transcription factor - spectrin - spectroscopy - src gene - src-family kinase - SSRI - starch - stem cell - stereochemistry - steroid 17alpha-monooxygenase - steroid 21-monooxygenase - steroid receptor - stimulatory gs G-protein - stoichiometry - structural biology - structural domain - Structural formula - structural motif - substance P - substrate - sugar - sulfur - supercoil - superfamily - superoxide - surface immunoglobulin - surface plasmon resonance - suspension (chemistry) - synapse - synthetic vaccine - systems biology

T
T cell - T-cell antigen receptors - tachykinin - tachykinin receptor - talin protein - tandem repeat sequence - taste bud - TATA box - tax gene product - taxonomy - telophase - tertiary structure - tetrodotoxin - thermochemistry - thermometer - thiamin - thioredoxin - threonine - thrombin - thrombin receptor - thrombomodulin - thromboxane receptor - thylakoid - thyroid hormone receptor - thyrotropin - thyrotropin receptor - thyrotropin-releasing hormone receptor - thyroxine - timeline of biology and organic chemistry - titration - tobacco mosaic virus - topoisomerase - toxin - trans-activator - transcription factor - transcription factor AP-1 - transducin - transformation - transforming growth factor - transforming growth factor alpha - transforming growth factor beta - transforming growth factor beta receptor - transient receptor potential - translation (biology) - transmembrane ATPase - transmembrane helix - transmembrane protein - transmembrane receptor - transport protein - transport vesicle - triiodothyronine - trinucleotide repeat - triose - tropomyosin - troponin - tryptophan - tubulin - tumor necrosis factors - tumor necrosis factor receptor - tyrosine - tyrosine 3-monooxygenase

U
ubiquitin - urea - urea cycle - uric acid - UV/VIS spectroscopy

V
vaccine - vacuole - valence - valine - van der Waals force - van der Waals radius - vapor pressure - vapour pressure - vasoactive intestinal peptide - vasoactive intestinal peptide receptor - vasopressin - vasopressin receptor - venom - vertebrate photoreceptor - vesicle - vestibular system - vimentin - viral envelope protein - viral oncogene protein - viral protein - virology - virus (biology) - vitamin - vitamin D-dependent calcium-binding protein - vitellogenin - vitronectin - von Willebrand factor

W
water

Y
Y chromosome - yeast

Z
zymology

title: Index of biochemistry articles


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Link rot

Link rot (also called link death, link breaking, or reference rot) is the phenomenon of hyperlinks tending over time to cease to point to their originally targeted file, web page, or server due to that resource being relocated to a new address or becoming permanently unavailable. A link that no longer points to its target, often called a broken, dead, or orphaned link, is a specific form of dangling pointer.

The rate of link rot is a subject of study and research due to its significance to the internet's ability to preserve information. Estimates of that rate vary dramatically between studies. Information professionals have warned that link rot could make important archival data disappear, potentially impacting the legal system and scholarship.

Commonly, broken website links may immediately redirect the user to the home page of the website, confusing users even more and resulting in it being difficult to obtain the URL of the broken link.

Prevalence
A number of studies have examined the prevalence of link rot within the World Wide Web, in academic literature that uses URLs to cite web content, and within digital libraries.

A 2002 study suggested that link rot within digital libraries is considerably slower than on the web, finding that about 3% of the objects were no longer accessible after one year (equating to a half-life of nearly 23 years).

A 2003 study found that on the Web, about one link out of every 200 broke each week, suggesting a half-life of 138 weeks. This rate was largely confirmed by a 2016–2017 study of links in Yahoo! Directory (which had stopped updating in 2014 after 21 years of development) that found the half-life of the directory's links to be two years.

A 2004 study showed that subsets of Web links (such as those targeting specific file types or those hosted by academic institutions) could have dramatically different half-lives. The URLs selected for publication appear to have greater longevity than the average URL. A 2015 study by Weblock analyzed more than 180,000 links from references in the full-text corpora of three major open access publishers and found a half-life of about 14 years, generally confirming a 2005 study that found that half of the URLs cited in D-Lib Magazine articles were active 10 years after publication. Other studies have found higher rates of link rot in academic literature but typically suggest a half-life of four years or greater. A 2013 study in BMC Bioinformatics analyzed nearly 15,000 links in abstracts from Thomson Reuters's Web of Science citation index and found that the median lifespan of web pages was 9.3 years, and just 62% were archived. A 2021 study of external links in New York Times articles published between 1996 and 2019 found a half-life of about 15 years (with significant variance among content topics) but noted that 13% of functional links no longer lead to the original content—a phenomenon called content drift.

A 2013 study found that 49% of links in U.S. Supreme court opinions are dead.

A 2023 study looking at United States COVID-19 dashboards found that 23% of the state dashboards available in February 2021 were no longer available at the previous URLs in April 2023.

Pew Research found that, in 2023, 38% of pages from 2013 went missing. Also in 2023, 54% of English Wikipedia articles had a dead link in the 'references' section and 23% of news articles linked to a dead URL.

Causes
Link rot can result from several occurrences. A target web page may be removed. The server that hosts the target page could fail, be removed from service, or relocate to a new domain name. As far back as 1999, it was noted that with the amount of material that can be stored on a hard drive, "a single disk failure could be like the burning of the library at Alexandria." A domain name's registration may lapse or be transferred to another party. Some causes will result in the link failing to find any target and returning an error such as HTTP 404. Other causes will cause a link to target content other than what was intended by the link's author.

Other reasons for broken links include:
 * the restructuring of websites that causes changes in URLs (e.g. domain.net/pine_tree might be moved to domain.net/tree/pine)
 * relocation of formerly free content to behind a paywall
 * a change in server architecture that results in code such as PHP functioning differently
 * dynamic page content such as search results that changes by design
 * deletion of the target page and/or its content
 * the presence of user-specific information (such as a login name) within the link
 * deliberate blocking by content filters or firewalls
 * the expiration of a domain name registration

Prevention and detection
Strategies for preventing link rot can focus on placing content where its likelihood of persisting is higher, authoring links that are less likely to be broken, taking steps to preserve existing links, or repairing links whose targets have been relocated or removed.

The creation of URLs that will not change with time is the fundamental method of preventing link rot. Preventive planning has been championed by Tim Berners-Lee and other web pioneers.

Strategies pertaining to the authorship of links include: Strategies pertaining to the protection of existing links include:
 * linking to primary rather than secondary sources and prioritizing stable sites
 * avoiding links that point to resources on researchers' personal pages
 * using clean URLs or otherwise employing URL normalization or URL canonicalization
 * using permalinks and persistent identifiers such as ARKs, DOIs, Handle System references, PURLs, or content addressing
 * avoiding linking to documents other than web pages
 * avoiding deep linking
 * linking to web archives such as the Internet Archive, WebCite, archive.today, Perma.cc, Amber, or Arweave
 * using redirection mechanisms such as HTTP 301 to automatically refer browsers and crawlers to relocated content.
 * using content management systems which can automatically update links when content within the same site is relocated or automatically replace links with canonical URLs
 * integrating search resources into HTTP 404 pages

The detection of broken links may be done manually or automatically. Automated methods include plug-ins for content management systems as well as standalone broken-link checkers such as like Xenu's Link Sleuth. Automatic checking may not detect links that return a soft 404 or links that return a 200 OK response but point to content that has changed.

title: Link rot


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Iyer

Iyers (also spelt as Ayyar, Aiyar, Ayer, or Aiyer) are an ethnoreligious community of Tamil-speaking Hindu Brahmins. Most Iyers are followers of the Advaita philosophy propounded by Adi Shankara and adhere to the Smarta tradition. This is in contrast to the Iyengar community, who are adherents of Sri Vaishnavism. The Iyers and the Iyengars are together referred to as Tamil Brahmins. The majority of Iyers reside in Tamil Nadu, India.

Iyers are further divided into various denominations based on traditional and regional differences. Like all Brahmins, they are also classified based on their gotra, or patrilineal descent, and the Veda that they follow. They fall under the Pancha Dravida Brahmana classification of Brahmins in India.

Apart from the prevalent practice of using the title "Iyer" as surname, Iyers also commonly use other surnames, such as Sāstri or Bhattar.

Etymology
Iyer (ஐயர், ) has several meanings in Tamil and other Dravidian languages, often referring to a respectable person. The Dravidian Etymological Dictionary lists various meanings for the term such as "father, sage, priest, teacher, brahman, superior person, master, king" with cognates such as tamayan meaning "elder brother" and simply ai "lord, master, husband, king, guru, priest, teacher, father". Linguistic sources often derive the words Ayya, Ayira/Ayyira as Prakrit versions of the Sanskrit word Aryā which means 'noble'.

In ancient times, Iyers were also called Anthanar or Pārppān, though the usage of the word Pārppān is considered derogatory in modern times. Until recent times, Kerala Iyers were called Pattars. Like the term pārppān, the word Pattar too is considered derogatory.

Population and distribution
Today, Iyers live all over South India, but an overwhelming majority of Iyers continue to thrive in Tamil Nadu. Tamil Brahmins form an estimated less than 3 per cent of the state's total population and are distributed all over the state. However, accurate statistics on the population of the Iyer community are unavailable.

Iyers are also found in fairly appreciable number in Western and Southern districts of Tamil Nadu. Iyers of the far south are called Tirunelveli Iyers and speak the Tirunelveli Brahmin dialect.

Migration

Over the last few centuries, many Iyers have migrated and settled in parts of Karnataka. During the rule of the Mysore Maharajahs, many Iyers from the then Madras province migrated to Mysore. The Ashtagrama Iyers are also a prominent group of Iyers in Karnataka.

Iyers have also been resident of the princely state of Travancore from ancient times. The Venad state (present Kanyakumari district) and the southern parts of Kerala was part of the Pandyan kingdom known as Then Pandi Nadu. There were also many Iyers in Venad which later on grew to be the Travancore state. The old capital of Travancore was Padmanabhapuram which is at present in Kanyakumari district. There has also been a continuous inflow from Tirunelveli and Ramnad districts of Tamil Nadu which are contiguous to the erstwhile princely state of Travancore. Many parts of the present Tirunelveli district were even part of the old Travancore state. These Iyers are known today as Trivandrum Iyers. Some of these people migrated to Cochin and later to Palakkad and Kozhikode districts. There were also migrations from Tanjore district of Tamil Nadu to Palakkad. Their descendants are known today as Palakkad Iyers. These Iyers are collectively now called as Kerala Iyers. In Coimbatore, there are many such Iyers due to its proximity to Kerala.

According to the Buddhist scripture Mahavamsa, the presence of Brahmins have been recorded in Sri Lanka as early as 500BC when the first migrations from the Indian mainland supposedly took place. Currently, Brahmins are an important constituent of the Sri Lankan Tamil minority. Tamil Brahmins are believed to have played a historic role in the formation of the Jaffna Kingdom.

Apart from South India, Iyers have also migrated to and settled in places in North India. There are significantly large Iyer communities in Mumbai, and Delhi. These migrations, which commenced during the British rule, were often undertaken in search of better prospects and contributed to the prosperity of the community.

In recent times Iyers have also migrated in significant numbers to the United Kingdom, Europe and the United States in search of better fortune.

Subsects
Iyers have many sub-sects among them, such as Vadama, Brahacharnam or Brahatcharanam, Vāthima, Sholiyar or Chozhiar, Ashtasahasram, Mukkāni, Gurukkal, Kāniyālar and Prathamasāki. Each sub-sect is further subdivided according to the village or region of origin.

Iyers, like all other Brahmins, trace their paternal ancestry to one of the eight rishis or sages. Accordingly, they are classified into eight gotras based on the rishi they have descended from. A maiden in the family belongs to gotra of her father, but upon marriage takes the gotra of her husband.

The Vedas are further sub-divided into shakhas or "branches" and followers of each Veda are further sub-divided based on the shakha they adhere to. However, only a few of the shakhas are extant, the vast majority of them having disappeared. The different Vedas and the corresponding shakhas that exist today in Tamil Nadu are:

Rituals
Iyer rituals comprise rites as described in Hindu scriptures such as Apastamba Sutra attributed to the Hindu sage Apastamba. The most important rites are the Shodasa Samaskāras or the 16 duties. Although many of the rites and rituals followed in antiquity are no longer practised, some have been retained.

Iyers are initiated into rituals at the time of birth. In ancient times, rituals used to be performed when the baby was being separated from mother's umbilical cord. This ceremony is known as Jātakarma. However, this practice is no longer observed. At birth, a horoscope is made for the child based on the position of the stars. The child is then given a ritual name. On the child's birthday, a ritual is performed to ensure longevity. This ritual is known as Ayushya Homam. This ceremony is held on the child's birthday reckoned as per the Tamil calendar based on the position of the nakshatras or stars and not the Gregorian calendar. The child's first birthday is the most important and is the time when the baby is formally initiated by piercing the ears of the boy or girl. From that day onwards a girl is expected to wear earrings.

A second initiation (for the male child in particular) follows when the child crosses the age of seven. This is the Upanayana ceremony during which a Brahmana is said to be reborn. A three-piece cotton thread is installed around the torso of the child encompassing the whole length of his body from the left shoulder to the right hip. The Upanayana ceremony of initiation is solely performed for the members of the dvija or twice-born castes, generally when the individual is between 7 and 16 years of age. In ancient times, the Upanayana was often considered as the ritual which marked the commencement of a boy's education, which in those days consisted mostly of the study of the Vedas. However, with the Brahmins taking to other vocations than priesthood, this initiation has become more of a symbolic ritual. The neophyte was expected to perform the Sandhya Vandanam on a regular basis and utter a prescribed set of prayers, three times a day: dawn, mid-day, and dusk. The most sacred and prominent of the prescribed set of prayers is the Gayatri Mantra, which is as sacred to the Hindus as the Six Kalimas to the Muslims and Ahunwar to the Zoroastrians. Once a year, Iyers change their sacred thread. This ritual is exclusive to South Indian Brahmins and the day is commemorated in Tamil Nadu as Āvani Avittam.

Other important ceremonies for Iyers include the rites for the deceased. All Iyers are cremated according to Vedic rites, usually within a day of the individual's death. The death rites include a 13-day ceremony, and regular Tarpanam (performed every month thereafter, on Amavasya day, or New Moon Day), for the ancestors. There is also a yearly shrārddha, that must be performed. These rituals are expected to be performed only by male descendants of the deceased. Married men who perform this ritual must be accompanied by their wives. The women are symbolically important in the ritual to give a "consent" to all the proceedings in it.

Festivals
Iyers celebrate almost all Hindu festivals like Deepavali, Navratri, Pongal, Vinayaka Chathurthi, Janmaashtami, Tamil New Year, Sivarathri and Karthika Deepam. An important festival, exclusive to Brahmins of South India, is the Āvani Avittam festival.

Weddings
A typical Iyer wedding consists of Sumangali Prārthanai (Hindu prayers for prosperous married life), Nāndi (homage to ancestors), Nischayadhārtham (Engagement) and Mangalyadharanam (tying the knot). The main events of an Iyer marriage include Vratam (fasting), Kasi Yatra (pilgrimage to Kasi), Oonjal (Swing), Kanyadanam (placing the bride in the groom's care), Mangalyadharanam, Pānigrahanam and Saptapathi (or seven steps - the final and most important stage wherein the bride takes seven steps supported by the groom's palms thereby finalizing their union). This is usually followed by Nalangu, which is a casual and informal event.

Traditional ethics
Iyers generally lead orthodox lives and adhere steadfastly to their customs and traditions. Iyers follow the Grihya Sutras of Apastamba and Baudhayana. The society is patriarchal but not feudal.

Iyers are generally vegetarian. Some abjure onion and garlic on the grounds that they activate certain base senses. Cow milk and milk products were approved. They were required to avoid alcohol and tobacco.

Iyers follow elaborate purification rituals, both of self and the house. Men are forbidden from performing their "sixteen duties" while women are forbidden from cooking food without having a purificatory bath in the morning. Food is to be consumed only after making an offering to the deities. The bathing was considered sufficiently purifying only if it conformed to the rules of madi. The word madi is used by Tamil Brahmins to indicate that a person is bodily pure. In order to practice madi, the Brahmin had to wear only clothes which had been recently washed and dried, and the clothes should remain untouched by any person who was not madi. Only after taking bath in cold water, and after wearing such clothes, would the person be in a state of madi. This practice of madi is followed by Iyers even in modern times, before participating in any kind of religious ceremony.

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Clothing

Iyer men traditionally wear veshtis or dhotis which cover them from waist to foot. These are made of cotton and sometimes silk. Veshtis are worn in different styles. Those worn in typical Brahminical style are known as panchakacham (from the sanskrit terms pancha and gajam meaning "five yards" as the length of the panchakacham is five yards in contrast to the veshtis used in daily life which are four or eight cubits long). They sometimes wrap their shoulders with a single piece of cloth known as angavastram (body-garment). In earlier times, Iyer men who performed austerities also draped their waist or chests with deer skin or grass.

The traditional Iyer woman is draped in a nine-yard saree, also known as madisār.

Patronage of art
For centuries, Iyers have taken a keen interest in preserving the arts and sciences. They undertook the responsibility of preserving the Natya Shastra, a monumental work on Bharatanatyam, the classical dance form of Tamil Nadu. During the early 20th century, dance was usually regarded as a degenerate art associated with devadasis. Rukmini Devi Arundale, however, revived the dying art of Sadir into the more "respectable" art form of Bharatanatyam, thereby breaking social and caste taboos about Brahmins taking part in the study and practice of dance. However many have claimed that, rather than becoming more open to other communities, the practice of Bharatanatyam was then restricted specifically to the middle and upper classes of Tamil society.

However, compared to dance, the contribution of Iyers in field of music has been considerably noteworthy.

Food
The main diet of Iyers is composed of vegetarian food, mostly rice which is the staple diet for millions of South Indians. Vegetarian side dishes are frequently made in Iyer households apart from compulsory additions as rasam, sambar, etc. Home-made ghee is a staple addition to the diet, and traditional meals do not begin until ghee is poured over a heap of rice and lentils. The cuisine eschews the extent of spices and heat traditionally found in south Indian cuisine. Iyers are mostly known for their love for curd. Other South Indian delicacies such as dosas, idli, etc. are also relished by Iyers. Coffee amongst beverages and curd amongst food items form an indispensable part of the Iyer food menu.

Housing
In ancient times, Iyers, along with Iyengars and other Tamil Brahmins, lived in exclusive Brahmin quarters of their village known as an agrahāram. Shiva and Vishnu temples were usually situated at the ends of an agrahāram. In most cases, there would also be a fast-flowing stream or river nearby.

A typical agrahāram consisted of a temple and a street adjacent to it. The houses on either side of the street were exclusively peopled by Brahmins who followed a joint family system. All the houses were identical in design and architecture though not in size.

With the arrival of the British and commencement of the Industrial Revolution, Iyers started moving to cities for their sustenance. Starting from the late 19th century, the agrahārams were gradually discarded as more and more Iyers moved to towns and cities to take up lucrative jobs in the provincial and judicial administration.

However, there are still some agrahārams left where traditional Iyers continue to reside. In an Iyer residence, people wash their feet first with water on entering the house.

Language
Tamil is the mother tongue of most Iyers residing in India and elsewhere. However, Iyers speak a distinct dialect of Tamil unique to their community. This dialect of Tamil is known as Brāhmik or Brahmin Tamil. Brahmin Tamil is highly Sanskritized and has often invited ridicule from Tamil purists due to its extensive usage of the Sanskrit vocabulary. While Brahmin Tamil used to be the lingua franca for inter-caste communication between different Tamil communities during pre-independence times, it has been gradually discarded by Brahmin themselves in favour of regional dialects.

Iyers today

In addition to their earlier occupations, Iyers today have diversified into a variety of fields. Three of India's Nobel laureates, Sir C. V. Raman, Subrahmanyan Chandrasekhar and Venkatraman Ramakrishnan hail from the community.

Since ancient times, Iyers, as members of the privileged priestly class, exercised a near-complete domination over educational, religious and literary institutions in the Tamil country. Their domination continued throughout the British Raj as they used their knowledge of the English language and education to dominate politics, administration, the courts and intelligentsia. Upon India's independence in 1947, they tried to consolidate their hold on the administrative and judicial machinery. Such a situation led to resentment from the other castes in Tamil Nadu, the result of this atmosphere was a "non-Brahmin" movement and the formation of the Justice Party. Periyar, who took over as Justice Party President in the 1940s, changed its name to Dravida Kazhagam, and formulated the view that Tamil Brahmins were Aryans as opposed to non-Brahmin Tamils who were Dravidian. The ensuing anti-Brahminism and the rising unpopularity of the Rajaji Government left an indelible mark on the Tamil Brahmin community ending their political aspirations. In the 1960s the Dravida Munnetra Kazhagam (roughly translated as "Organisation for Progress of Dravidians") and its subgroups gained political ground on this platform forming state ministries, thereby wrenching control from the Indian National Congress, in which Iyers at that time were holding important party positions. Today, apart from a few exceptions, Iyers have virtually disappeared from the political arena.

In 2006, the Tamil Nadu government took the decision to appoint non-Brahmin priests in Hindu temples in order to curb Brahmin ecclesiastical domination. This created a huge controversy. Violence broke out in March 2008 when a non-Brahmin oduvar or reciter of Tamil idylls, empowered by the Government of Tamil Nadu, tried to make his way into the sanctum sanctorum of the Nataraja temple at Chidambaram.

Relations with other communities
The legacy of Iyers have often been marred by accusations of racism and counter-racism against them by non-Brahmins and vice versa.

Grievances and instances of discrimination by Brahmins are believed to be the main factors which fuelled the Dravidian Movement. With the dawn of the 20th century, and the rapid penetration of western education and western ideas, there was a rise in consciousness amongst the lower castes who felt that rights which were legitimately theirs were being denied to them. This led the non-Brahmins to agitate and form the Justice Party in 1916, which later became the Dravidar Kazhagam. The Justice Party banked on vehement anti-Hindu and anti-Brahmin propaganda to ease Brahmins out of their privileged positions. Gradually, the non-Brahmin replaced the Brahmin in every sphere and destroyed the monopoly over education and the administrative services which the Brahmin had previously held.

The concept of "Brahmin atrocities" is refuted by some Tamil Brahmin historians. They argue that allegations of casteism against Tamil Brahmins have been exaggerated and that even prior to the rise of the Dravida Kazhagam, a significant section of Tamil Brahmin society was liberal and anti-casteist, for example the Temple Entry Proclamation passed by the princely state of Travancore which gave people of all castes the right to enter Hindu temples in the princely state was due to the efforts of the Dewan of Travancore, Sir C. P. Ramaswamy Iyer who was an Iyer.

Dalit leader and founder of political party Pudiya Tamizhagam, Dr. Krishnasamy admits that the Anti-Brahmin Movement had not succeeded in improving the rights of Dalits and that there continues to be as much discrimination of Dalits as had been before.

"So many movements have failed. In Tamil Nadu there was a movement in the name of anti-Brahmanism under the leadership of Periyar. It attracted Dalits, but after 30 years of power, the Dalits understand that they are as badly-off - or worse-off - as they were under the Brahmans. Under Dravidian rule, they have been attacked and killed, their due share in government service is not given, they are not allowed to rise."

Alleged negative attitude towards Tamil language and culture
Iyers have been called Sanskritists who entertained a distorted and contemptuous attitude towards Tamil language, culture and civilization. The Dravidologist Kamil Zvelebil says that the Brahmin was chosen as a scapegoat by the Dravidian parties to answer for the decline of Tamil civilization and culture in the medieval and post-medieval periods. Despite these allegations many Iyers were great contributors to the Tamil language. Agathiar, usually identified with the legendary Vedic sage Agastya is credited with compiling the first rules of grammar of the Tamil language. Moreover, individuals like U. V. Swaminatha Iyer and Subramanya Bharathi have made invaluable contributions to Tamil literature. Parithimar Kalaignar was the first to campaign for the recognition of Tamil as a classical language.

Portrayal in popular media
Brahmins are mentioned for the first time in the works of Sangam poets. During the post sangam era, Brahmin saints have been frequently praised for their efforts in combating Buddhism. In modern times, when Iyers and Iyengars control a significant percentage of the print and visual media, there has been significant coverage of Brahmins and Brahmin culture in magazines and periodicals and a number of Brahmin characters in novels, TV serials and films.

Their portrayal in media started to become more negative with the rise of Dravidian political movements. The writings and speeches of many Dravidian political activists such as Iyothee Thass, Maraimalai Adigal, Periyar, Bharatidasan, C. N. Annadurai, the leaders of Justice Party in the early 20th century and of the Dravidar Kazhagam in more modern times constitute much of modern anti-Brahmin rhetoric.

Starting from the 1940s onwards, Annadurai and the Dravida Munnetra Kazhagam have been using films and the mass media for the propagation of their political ideology. Most of the films made, such as the 1952-blockbuster Parasakthi written by future Chief minister M. Karunanidhi, are anti-Brahminical in character.

Notable people
Some of the early members of the community to gain prominence were sages and religious scholars like Agatthiar, Tholkappiyar (Tirunadumakini), Parimelalhagar and Naccinarkiniyar. Prior to the 19th century, almost all prominent members of this community hailed from religious or literary spheres. Tyagaraja, Syama Sastri and Muthuswamy Dīkshitar, who constitute the "Trinity of Carnatic music" were probably the first verified historical personages from the community, as the accounts or biographies of those who lived earlier appear semi-legendary in character. Most of the Dewans of the princely state of Travancore during the 19th century were Tamil Brahmins (Iyers and Iyengars).

 * Nethra Raghuram, Indian model who won Femina Magazine Look of the Year contest 1997
 * Shankar Mahadevan, Music director

title: Iyer