text:
Talk:Royal house

What happened to noble houses?
Noble houses/dynasties dont have their own page, why ever not? They arent even mentioned on this page! Noble houses are almost, if not as important, as royal houses! Does anyone have a reason for their entire exclusion from wikipedia? --Camaeron (talk) 17:53, 10 March 2008 (UTC)

Question, I was under the impression that the ruling house in Portugal at the time of their deposition was Saxe-Coburg-Gotha?

--Dudeness10 16:46, 4 October 2005 (UTC)

 * No as the article House of Braganza-Saxe-Coburg and Gotha says. The last four Portuguese kings used the term Braganza to refer to themselves rather than Braganza-Saxe-Coburg and Gotha which is used by others outside Portugal.--Queen Elizabeth II's Little Spy (talk) 18:33, 17 July 2011 (UTC)

I'm not so sure the Austria description is correct. Dr. Otto von Hapsburg signs his name as such, not as Habsburg-Lothringen. I believe the name of the ruling house of Austria was Habsburg-Lothringen (or Habsburg-Lorraine in English) for the descendants of Francis of Lorraine and Maria Theresia of Austria, as House names are usually changed when the succession is through a female - but as a surname, it's just plain von Hapsburg/Habsburg. This is a case where the House name as usually given (just plain Habsburg) isn't technically correct, like the "House of Romanov" -- Someone else 23:53 Jan 22, 2003 (UTC)

Toying with these here before adding to article, as much has to be worked out and it is "neater" if it's done here. Many of the surnames are seldom if ever actually used: "The members of many royal houses use surnames so rarely that their surnames, if any, cannot be discerned with certainty."

 * Belgium
 * house: Saxe-Coburg-Gotha? Wettin?
 * surname:
 * Denmark
 * house: Glücksborg; Schleswig-Holstein-Sonderburg-Glücksborg?
 * previous houses: Oldenburg
 * surname:
 * Liechtenstein
 * house: Liechtenstein
 * surname:
 * Luxembourg
 * house: Nassau
 * surname:
 * Monaco (serene, not royal)
 * house: Grimaldi
 * surname: Grimaldi
 * Netherlands
 * house: Orange-Nassau; Oranje-Nassau
 * surname: titles and surnames individually set by decree; presumably van Amsberg for most of the current queen's children
 * Norway
 * house: Glücksborg
 * surname:
 * Spain
 * house: Borbón
 * surname: Borbón ?
 * Sweden
 * house: Bernadotte
 * surname: Bernadotte
 * United Kingdom
 * house: Windsor
 * previous houses: Plantagenet, Lancaster, York, Tudor, Stuart, Hanover, Saxe-Coburg-Gotha
 * surname: Mountbatten-Windsor
 * previous surnames: Guelph, Welf...

deposed and pretending:
 * Austria:
 * house: Habsburg-Lothringen
 * surname: Habsburg; head of house is "von Habsburg"; many use no surname
 * Bavaria:
 * house: Wittelsbach
 * surname:
 * France: (royal)
 * house: Bourbon-Orléans
 * surname: often use 'France' as surname
 * France: (Imperial)
 * house: Bonaparte
 * surname:
 * France: (Legitimist)
 * house: Borbón-Parma
 * surname:
 * Germany:
 * house: Hohenzollern
 * surname:
 * Greece:
 * house: Gluckberg or Schleswig-Holstein-Sonderburg-Glücksburg?
 * surname: Oldenberg?
 * Hungary:
 * house: Habsburg-Lothringen
 * surname:
 * Italy:
 * house: Savoy
 * surname:
 * Rumania:
 * house: Hohenzollern
 * surname:
 * Russia:
 * house: usually given as Romanov but technically Holstein-Gottorp-Romanov
 * surname: used Romanov [m] or Romanova [f]

Question: I thought Bourbon, not Orleans, is the Legitimist name, as in those who insist that someone other than the Comte de Paris is the true pretender, ie those who in the 19th century backed the Comte de Chambord ('Henry V'), But then Legitimists were divided between those who backed the Comte de Paris as next in line after Chambord's death, and those who insisted 'absolutely not' and now see some Spanish man as the 'real' heir. So did you mean Legitimist in the 19th century sense or in the sense of the majority of modern French monarchists, who back the current Comte de Paris? (God I thought the Irish Famine was complicated!!!) Maybe, as most people who follow the complicated history of French royalism would know it through the disputes over heirs to Charles X and Louis-Philippe, we should use 'Legitimist' and 'Orleanist' in their nineteenth century meaning? (Except of course, the Orleanist pretender is the legitimate pretender to the majority of royalists. Aaaaagh. Even I'm confused now!) JTD 20:01 Jan 23, 2003 (UTC)

I agree, three French kings is too many and it makes me numb too, You are right of course about Bourbon. (One reason I put this stuff here was so the "good guys" could check it first.) It occurs to me that another way to present this would be by houses. When I tried to find surnames it seems to me even more true that [1] most of these houses really have no "official" surname, and [2] even if they have one, it's never used. But if you (or anyone) can fill in any surnames I'd be very happy to learn them!. As you'll see below, I really need to get my French & Nassau refs out -- Someone else 00:27 Jan 24, 2003 (UTC)

 * Houses
 * name - surname - rank - rules - once ruled - name used
 * Zogu - Zogu - royal - - Albania
 * Ascania - - ducal -  - Anhalt
 * Habsburg-Lorraine - Habsburg - imperial - - Austria
 * Zähringen - - grand-ducal -  - Baden
 * Wittelsbach - - royal -  - Bavaria
 * Saxe-Coburg-Gotha - - royal - Belgium -
 * Bonaparte - Bonaparte - imperial - - France
 * Borbón - Bourbón-Orléans - royal - - France - Count of Paris
 * Borbón - Bourbón-Parma - ducal - - Parma - Duke of Parma
 * Borbón - Bourbón-Two Sicilies - royal - - Two-Sicilies - Duke of Calabria
 * Orléans-Bragança - - imperial -  - Brazil - Prince of Orléans & Bragança
 * Saxe-Coburg-Gotha - - royal -  - Bulgaria -

Houses with subhouses
 * Ascania
 * Anhalt
 * Saxe-Lauenburg
 * Saxe-Wittenberg
 * Anhalt-Dessau
 * Anhalt-Bernburg
 * Anhalt-Köthen
 * Plotzkau
 * Anhalt-Zerbst

 * Capet
 * 1st house of Burgundy
 * house of Portugal
 * house of Montagu
 * house de Couches
 * house de Viennois
 * house of Vermandois
 * House of Chaumont
 * house of Dreux
 * House of Bretagne
 * house of Machecoul
 * House of Beu
 * House of Courtenay
 * House of Artois
 * 1st house of Anjou
 * Bourbon
 * Bourbon-La March
 * Bourbon-Vendome
 * 2nd house of Bourbon-Montpensier
 * Bourbon-Conde
 * Bourbon-Orleans
 * Orléans-Bragance
 * Orléans-Galliera
 * Bourbon-Anjou
 * Bourbon-Carency
 * 1st house of Bourbon-Montpensier
 * Valois
 * Alençon
 * 2nd House of Anjou
 * 2nd House of Burgundy
 * Valois-Orléans
 * Valois-Angoulême
 * House of Evreux

 * Habsburg
 * Habsburg-Lorraine
 * Tuscany	(grand dukes)
 * Teschen	(dukes)
 * Palatines of Hungary

 * Schleswig-Holstein-Sonderburg-Glücksburg
 * Glücksburg
 * Oldenburg

 * Lorraine-Brabant
 * Hesse (Landgraves of Hesse)
 * Hesse-Cassel
 * Hesse-Philippsthal
 * Hesse-Philippsthal-Barchfeld
 * Hesse-Darmstadt
 * Hesse-and-by-Rhine

 * Holstein (Oldenburg)
 * Holstein-Sonderburg
 * Schleswig-Holstein-Sonderburg-Augustenburg
 * Schleswig-Holstein-Sonderburg-Glücksborg
 * Holstein-Gottorp
 * Holstein-Gottorp
 * Oldenburg

 * Lippe
 * Lippe
 * Lippe-Weissenfeld

 * Mecklenburg
 * Mecklenburg-Schwerin
 * Mecklenburg-Strelitz

 * Nassau
 * Orange-Nassau
 * Wettin (Saxony)
 * Ernestine line
 * Saxe-Weimar-Eisenach
 * Gotha branch
 * Saxe-Meiningen
 * Hildburghausen, later Saxe-Altenburg
 * Coburg-Saalfeld, later Saxe-Coburg and Gotha
 * Albertine line
 * Saxe

I'm impressed by your knowledge. Frequently on Wiki you come across people with a bit of information and one hell of an agenda. But you also come across people who know a hell of a lot, sometimes more than they realise until they start writing articles. Reading contributions from people who clearly know what they are talking about, or are well on the way to getting there, is one of the fun bits of being on Wiki. JTD 00:46 Jan 24, 2003 (UTC)

 * Thanks for your kind words. Like you, I find it most enjoyable here when people cooperate and can actually learn from each other. Edit wars just raise the blood-pressure, not the level of knowledge.  -- Someone else 06:36 Jan 24, 2003 (UTC)  PS...ah, yes, the agenda can be a real killer on some of these articles.  Much better to be obsessed over saying one thing exactly true, than insisting on perpetrating propaganda.

You forgot Poland Sigmaringen. :D

The Frederick 10:12, 25 January 2006 (UTC) -

This talk of House and Surname is somewhat crazy in some of these cases. The idea of 'surname' isnt really integral to the concept of 'royalty'. Even when the British royal family decided to change their german "surname" to something suitably english - they had to do considerable guesswork deciding what that surname actually was. The discussions end up being silly - noone is an authority and their isnt some rule that can be applied. Its often a matter of personal taste with these people. tridesch Jan 23, 2003 (UTC)

 * When Queen Victoria was asked what her surname was she replied that she thought it might be Guelph or possible Welf. Which was a view then au courrant, but of little validity. -- Someone else 06:36 Jan 24, 2003 (UTC)

True, but some people foolishly have been trying to put royals on Wiki through what they think (usually wrongly) is the surname; eg, 'Charles Windsor' for the Prince of Wales, whose actual surname according to Buckingham Palace is Mountbatten-Windsor, not that he ever uses it. The point of this and related pages is to get through to people that you cannot simply add 'makey-uppy' surnames on Wiki, or even worse, demand that royals be referred to only by non-existent surnames. The only workable solution is to rely on their title, as in Charles, Prince of Wales, Anne, Princess Royal etc. with a Royal House reference in the text to clarify which Royal Family they actually belong to. (Though unlike most royals, ironically Anne and Charles do have a surname!) JTD 01:52 Jan 24, 2003 (UTC)

 * Part of the reason JTD came up with a Royal House page at all is to discourage the use of made-up surnames. And one of the very interesting things that I'm finding out from [1] looking into it and [2] not having many surnames show up here in response to my ignorance of same, is that it's the rare royal or even formerly reigning house that has anything approaching a "normal" or standard surname.  So words to that effect will be of benefit in the article.  Something along those lines, and pointing out the somewhat ironic point that most the surnames of most commoners are more ancient than those of royals who have recently adopted surnames.. -- Someone else 06:36 Jan 24, 2003 (UTC)

Habsburgs and Romanovs
One of my uncles (who was born in the 1920s) was adopted. With great difficulty he traced his birth parents in the 1960s. It turned out he was a bastard of the Habsburgs and was born with the surname Edler von Kirsch. There was some connection with the Romanov dynasty - way, way back - anyone know the link? David Cleghorn (davidcleghorn32@hotmail.com).

Question over Saxe-Coburg-Gotha
I am afraid that this line is incorrect "imilarly, though the British Royal House name under Queen Victoria and King Edward VII was Saxe-Coburg-Gotha, the personal surname of Victoria's descendants was Wettin." I was under the impression that under Victorias reign, it was still the House of Hanover, as decended from George, Elector of Hanover. When Victoria died, Edward VII did take the name of his fathers family, Saxe-Cobug-Gotha. I am going to edit to show this unless someone can prove otherwise?

--Dudeness10 8 July 2005 17:18 (UTC)

 * Victoria was the last of the House of Hanover to rule over Britain. However, on that surname thing, she took her husband's name, which was found in ancient times to be Wettin, as women take their husband's name upon marriage, as they still do now in Western countries.Emerson 07 (talk) 02:48, 16 July 2010 (UTC)

 * British royal during the House of Hanover and Saxe-Coburg and Gotha didn't use surnames; the Windsors, the Tudors, the Stuarts did. Queen regnants don't take on their husband's name or royal house; their children do. --Queen Elizabeth II's Little Spy (talk) 18:31, 17 July 2011 (UTC)

Why know Grimaldi?(sp?)
The Royal house of Monaco is missing, why?
 * There is no such thing as Royal house of Monaco. Monaco is ruled by a Prince who belongs to the Princely House of Grimaldi. Surtsicna (talk) 18:47, 24 September 2008 (UTC)

Liechtenstein
The royal house of Liechtenstein isn't included... Sotakeit 20:01, 15 April 2006 (UTC)
 * Because it's not a royal house. It's a princely house. Surtsicna (talk) 18:47, 24 September 2008 (UTC)

Merge proposal
For discussion of this proposal, please see Talk:Dynasty. FactStraight (talk) 05:49, 29 June 2008 (UTC)

Israel..
Israel is a modern state which ever since its inception has not had Royalty.

The Davidic line as well as the Hasmonean dynasty did not rule the modern state of Israel and as such they are not extinct houses of the modern state of Israel. --92.40.65.116 (talk) 18:44, 20 October 2008 (UTC)
 * Just link it to Kingdom of Israel, I don't see the problem...--Cameron* 11:40, 21 October 2008 (UTC)

That would be correct in the case of the Davidic line, but is it wise to turn this article into one about every single ancient historical kingdom in existence?

Most of the countries mentioned would require an article for themselves to deconstruct their previous re-incarnations and legendary as well as historical Royalty. --92.40.35.23 (talk) 18:00, 21 October 2008 (UTC)
 * You are right. I will be shortening the list anyway, shortly. --Cameron* 18:01, 21 October 2008 (UTC)

Volgaland
I removed it from the entry on reigning houses. It's not a reigning house by any standards. Gerard von Hebel (talk) 23:00, 7 February 2009 (UTC)

Brunei
I'm adding Brunei (House of Bolkiah) top the list of extant sovereign houses. I see no reason it should be omitted.87.139.126.43 (talk)

___ ZULU KINGS Zweletini

What about the Zulu royal house of Zweletini??? —Preceding unsigned comment added by 193.58.71.208 (talk) 07:42, 3 July 2009 (UTC)

Headship of Royal Houses
Could anyone please enlighten me as to what are the rules of succession on headship to royal houses? Currently, I believe that it passes through agnatic primogeniture. The prominence of status of a woman does not elevate her to the headship of the house - i.e. Queen Elizabeth II or Prince Richard, Duke of Gloucester as Head of the House of Windsor (Saxe-Coburg-Gotha branch) - or does it? Emerson 07 (talk) 02:55, 16 July 2010 (UTC)
 * that is different for each house, and it can be changed to fit circumstances. For example, see Salic_law, where the old Salic law was resurrected and strengthened to forbid the inheritance of kingship via female lines. All in order to refute the claim of a certain royal house. The article lists more examples for Spain, Britain, one German state, the Netherlands, Luxembourg and Normandy, where the law had to be changed to forbid (or to allow) inheritance by females. --Enric Naval (talk) 16:41, 16 July 2010 (UTC)

The headship of houses and the claims to thrones are independent of each other. In Denmark, the throne was inherited in 1863 by a junior member of a cadet branch of the House of Oldenburg, mostly because his wife was a close relative of the childless, last Oldenburg king. The Danish monarchs have never claimed to be heads of their house (House of Glücksburg or House of Oldenburg), instead, the descendants of the elder brother of Christian IX of Denmark are the heads of the house. Garn Svend (talk) 14:51, 4 May 2011 (UTC)

Suggest moving the page
The term house, referring to family, is actually not only used for royal houses, but also frequently for (other) noble houses, both souvereign and non-souvereign. A better title would be house (family). Garn Svend (talk) 14:47, 4 May 2011 (UTC)

 * Oppose. This article is about sovereign houses (royalty), and this is defined as "in common parlance members of any family which reigns by hereditary right are often referred to as royalty or "royals". It is also customary in some circles to refer to the extended relations of a deposed monarch and his or her descendants as a royal family." If this list will be about all noble houses, this will be extremely long, as every peerage or noble family is "noble house".--Yopie (talk) 18:06, 4 May 2011 (UTC)
 * Oppose, per Yopie. If this article is to be re-named it should be to "Sovereign Houses". If it is to be merged with another article it should be Dynasty. FactStraight (talk) 19:06, 17 July 2011 (UTC)
 * Support12.28.236.6 (talk) 22:44, 22 July 2011 (UTC)
 * Support184.98.204.157 (talk) 05:22, 23 July 2011 (UTC)
 * Note for closing admin Both IP´s above are sockppupets, see Sockpuppet investigations/12.28.236.6. --Yopie (talk) 21:21, 23 July 2011 (UTC)
 * Support208.248.82.6 (talk) 00:30, 26 July 2011 (UTC)
 * Support71.35.17.152 (talk) 08:03, 7 August 2011 (UTC)
 * Note for closing admin 208 IP blocked for sock puppetry. 71 IP geolocates to Phoenix Arizona like other blocked IPs. DeCausa (talk) 08:08, 7 August 2011 (UTC)
 * 71.35 has just been blocked as yet another sock. Favonian (talk) 09:49, 7 August 2011 (UTC)

List of royal houses
I was going to split this article per a long standing split tag, however I found that article already exists and at cursory inspection duplicates the information in the list in this article. Would there be any objection to me moving any information in the list in this article that is not in the List of royal houses articles and removing the list in this article? Op47 (talk) 17:06, 1 January 2012 (UTC)
 * No objection from me. --Enric Naval (talk) 13:33, 21 July 2012 (UTC)

title: Talk:Royal house


text:
Napier Nomad

The Napier Nomad is a British diesel aircraft engine designed and built by Napier & Son in 1949. They combined a piston engine with a turbine to recover energy from the exhaust and thereby improve fuel economy. Two versions were tested, the complex Nomad I which used two propellers, each driven by the mechanically independent stages, and the Nomad II, using the turbo-compound principle, coupled the two parts to drive a single propeller. The Nomad II had the lowest specific fuel consumption figures seen up to that time. Despite this the Nomad project was cancelled in 1955 having spent £5.1 million on development, as most interest had passed to turboprop designs.

Design and development
In 1945 the Air Ministry asked for proposals for a new 6000 hp class engine with good fuel economy. Curtiss-Wright was designing an engine of this sort of power known as the turbo-compound engine, but Sir Harry Ricardo, one of Britain's great engine designers, suggested that the most economical combination would be a similar design using a diesel two-stroke in place of the Curtiss petrol engine.

Before World War II Napier had licensed the Junkers Jumo 204 diesel design to set up production in the UK as the Napier Culverin, but the onset of the war made the Sabre all-important and work on the Culverin was stopped. In response to the Air Ministry's 1945 requirements Napier dusted off this work, combining two enlarged Culverins into an H-block similar to the Sabre, resulting in a massive 75 litre design. Markets for an engine of this size seemed limited, however, so instead they reverted to the original Sabre-like horizontally opposed 12 cylinder design, and the result was the Nomad.

The objective of the design was to produce a civilian power plant with far superior fuel efficiency to the emerging jet engine. Thermal efficiency is given by $$1 - T_e/T_p$$, where T$e$ is the exhaust temperature in kelvins and T$p$ is the peak combustion temperature. Jet engines have relatively low-temperature combustion systems which produce a T$p$ of no more than about 1,000 K, much less than the typical 5,000 K of a reciprocating engine, and so jets have very poor thermal efficiency. The Nomad design focused on replacing the low-temperature combustion chambers of the jet engine with highly efficient Diesel combustion chambers. In practice, it was much too difficult to couple the diesel power output back into the turbine cycle. The maximum practical power of the Nomad was 4000 hp, and it was much heavier than a pure jet of the same power. By this time civilian jets such as the Boeing 707 were nearing completion, and the Nomad was never seriously considered by any aircraft manufacturer.

Nomad I
The initial Nomad design (E.125) or Nomad 1 was incredibly complex, almost two engines in one. One was a turbo-supercharged two-stroke diesel, having some resemblance to half of a Napier Sabre's H-24. Mounted below this were the rotating parts of a turboprop engine, based on the Naiad design, the output of which drove the front propeller of a contra-rotating pair. To achieve higher boost, the crankshaft drove a centrifugal supercharger, which also provided the scavenging needed for starting the engine from rest. During take-off additional fuel was injected into the rear turbine stage for more power, and turned off once the aircraft was cruising.

The compressor and turbine assemblies of the Nomad were tested during 1948, and the complete unit was run in October 1949. The prototype was installed in the nose of an Avro Lincoln heavy bomber for testing: it first flew in 1950 and appeared at the Farnborough Air Display on 10 September 1951. In total the Nomad I ran for just over 1,000 hours, and proved to be rather temperamental, but when running properly it could produce 3000 hp and 320 lbf thrust. It had a specific fuel consumption (sfc) of 0.36 lb/hph.

The prototype Nomad I is on display at the National Museum of Flight at East Fortune Airfield in Scotland.

Nomad II
Even before the Nomad I was running, its successor, the Nomad II (E.145) Nomad 6, had already been designed. In this version an extra stage was added to the axial compressor/supercharger, eliminating the separate centrifugal part and the intercooler. The turbine (which also received an additional stage) was now only used to drive the compressor, and feed back any excess power to the main shaft using a Beier variable-ratio gear; the separate propeller from the turbine was deleted, just as the whole of the "afterburner" system with its valves etc. So the system was now like a combination of a mechanical supercharger, and a turbocharger without any need for bypass. The result was smaller and considerably simpler: a single engine driving a single propeller. Overall weight reduction was 1000 lb. The wet liners of the cylinders of the Nomad I were changed for dry liners.

While the Nomad II was undergoing testing, a prototype Avro Shackleton was lent to Napier as a testbed. The engine proved bulky, like the Nomad I before it, and in the meantime several dummy engines were used on the Shackleton for various tests.

On an equivalent power basis, the Nomad II had an SFC of 0.327 lb/hph at 25000 ft cruise altitude.

A further development, the Nomad Nm.7, of 3500 shp was announced in 1953.

By 1954 interest in the Nomad was waning, and after the only project, the Avro Type 719 Shackleton IV, based on it was cancelled, work on the engine was ended in April 1955, after an expenditure of £5.1 million. The design was also considered for the Canadair Argus, a similar maritime patrol aircraft being designed for the Royal Canadian Air Force. This design turned to the Wright R-3350, the design the Nomad was intending to best.

A Nomad II is on display at the Steven F. Udvar-Hazy Center in Virginia.

Applications

 * Airspeed Ambassador (planned only)
 * Avro Lincoln (test bed only)
 * Avro Shackleton (planned only)
 * Canadair CP-107 Argus (planned only)

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

title: Napier Nomad


text:
Talk:Diff

Subsequence vs. substring
This article mentions the longest common substring algorithm, but shouldn't it be subsequence? 129.241.124.103 (talk) 21:07, 10 July 2013 (UTC)
 * Hmm, I'm rambling. It *is* subsequence, but for some reason I had the substring page up in another tab, and thought I clicked it from here. 129.241.124.103 (talk) 21:14, 10 July 2013 (UTC)

Diff3
Another contributor and myself are unsure whether some of the information on diff3 is accurate. Specifically, we do not fully agree (for lack of knowledge, rather than conflicting knowledge) on the evolution of diff3, its current relevance to users, and its technical relationship to the merge utitlity. Any contributions and corrections (with references, please!) are welcomed. (However, having just looked at the GNU diff3 source, I have to say that it's such a simple-minded program that I doubt it's worthy of further analysis).

Diff Feature Comparison
This feature comparison matrix in its current existence looks really superficial. It's a good idea, but I don't think very many software articles on WikiPedia serve as running software reviews of different packages. Most of these diff applications are graphical interfaces anyway.

Diff on Wikipedia
Anyone know what diff program Wikipedia uses for its page histories, which shows the spefic location in a line where text begins to differ, or what such a program would be called? This seems to be slightly different from the UNIX program which only shows differing lines but not where in the line it differs.

 * Wikipedia currently doesn't use diff at all, the history functionality is being done by MediaWiki and is code written in PHP. I imagine this includes the functionality showing results on a word-by-word basis --132.198.104.111 17:38, 13 Jul 2004 (UTC)

 * So is there any piece of software that does this thing for files? -- 193.226.167.123 17:52, 20 March 2006 (UTC)

 * If any of my reverted edits were allowed to remain or if my merge proposal wasn't voted down, this discussion might not be necessary.

 * Wikipedia uses a file comparison utility that works when you click "diff." It might not be the Unix diff program though. File comparison utilities that might do what you want are listed in various sections at the bottom of this article, and on the bottom of the file comparison page. One of the links at Help:Contents might lead you to more information.

 * Usability is dead. -Barry- 18:41, 20 March 2006 (UTC)

 * Thanks! I just found something that looks somewhat promising (the external link at Help:Diff in the "Tracking changes" section). -- 193.226.167.123 19:16, 20 March 2006 (UTC)

In Unix land there's something called Wdiff. --65.19.87.53 01:35, 22 March 2006 (UTC)

This article should probably mention the use of diff pages on Wikipedia. They are a pretty accessible example of diff pages in broader (non-strictly-software) use. -Bonus Onus (talk) 15:54, 21 January 2009 (UTC)

Layman's Terms
Could some one explain this in layman's terms?

 * The diff algorithm is an implementation of the Longest-common subsequence problem, which is now linked to in Diff's "See also" section.

 * I've added an example for clarity. I don't say it's a good (or realistic) example, but it will do for now. Without an example it's not clear what a diff really is, or looks like. --Shinobu 18:14, 28 Mar 2005 (UTC)

Binary v. Text Sentence in Intro
Apart from that, shouldn't "The first editions of the program were designed for line comparisons in text files. By the 1980s, support for binary files was necessary resulting in a shift in the application's design." be in the History section? Just a thought. --Shinobu 18:14, 28 Mar 2005 (UTC)

 * I agree it seems out of place, but I think it's necessary to somehow mention in the intro that diff handles text and binary data.  The sentence is just being a little more specific.  No worries.

Why I deleted Unix and the $-sign
I deleted Unix from the intro because there are diffs for every platform. The Unix heritage is discussed in the History section so I think that's okay. I removed the $-sign, because prompts look different on every system (even if one compares two Unixen). Apart from that, most texts illustrating a command to be entered don't display the prompt, because it might be confused with input that has to be entered by the user. Bye, Shinobu 18:12, 25 Apr 2005 (UTC)

Not enough said about patch(1)
I think the page should have a little more about patch(1) - not the whole content of patch's page, but a short introduction and a link to the page; elsewhere than in the GNU advertisements or "See also" section. I might write something when I have time.

I've added a sentence to the History section. It could probably use mentioning in the top section, I couldn't think of what. --132.198.104.164 17:49, 15 July 2005 (UTC)

Where to list DiffNote
DiffNote parses the output of the GNU diff command 'diff -y' and it's a free web application. I originally listed it under Free software implementations, but someone moved it to External links because it's not software and it's a web app. I think it is a free software implementation, as in an implementation of software, and the description of Free software implementations fits it. I don't want to revert it back to the Free software implementations section because it's my web app and some people might say I shouldn't even have posted it in the first place, but if there's agreement here that it belongs under Free software implementations, I'll move it back. -Barry- 19:56, 25 February 2006 (UTC)

 * I do not think it is an implementation as it is merely parsing diff's output, according to you. --maru (talk) contribs 20:24, 25 February 2006 (UTC)

 * I'm not sure whether parsing is the right word. DiffNote shows invisible characters as red dots, while 'GNU diff -y' renders them. If you use 'GNU diff -y' on a line that has a carriage return in the middle of the text, the CR will cause the text after the CR to show at the beginning of the line and the text that was at the beginning of the line in the file you were diffing won't be shown. In DiffNote, all text is shown and the CR is represented by a red dot (which will eventually be titled "ASCII 13" so you'll know exactly what it represents). The order of the lines in the output, and (essentially) the gutter markers are the same as in 'GNU diff -y' but other things, like the red dots, are different. -Barry- 20:41, 25 February 2006 (UTC)

Patience diff
There seems to be increasing interest in the use of the patience diff algorithm, particularly for revision control. In particular, Codeville's precise merge algorithm (pcvd) employs it, and there has been interest in employing it for Bazaar-NG (see https://lists.ubuntu.com/archives/bazaar-ng/2005q4/005971.html, https://lists.ubuntu.com/archives/bazaar-ng/2006q2/010652.html). I've seen a few references (including Codeville's own documentation for pcvd at http://revctrl.org/PreciseCodevilleMerge) that point to the Patience sorting article.

 * Longest-common subsequence problem doesn't mention Patience sorting.
 * Patience sorting has a section "Algorithm for finding the longest increasing subsequence", but doesn't link to Longest-common subsequence problem.
 * This article (diff) doesn't mention Patience sorting's applicability to diffing/patching.

I feel that this is something that wikipedia could treat better, but I'm not sure how to go about it.

— Daf 19:59, 21 May 2006 (UTC)

Diff links
You're allowed to think the numerous links on the Diff page are "useful", but that's not the measuring bar. The links I deleted are not relevant to the diff command. They're neat little Web sites that do the similar task that Diff does, but every generic Web file comparison tool can't be expected to be listed. After reviewing all of them, I did allow one Web site of note that provides output similar to using the actual Diff command. A lot of them are just more of the same thing and pollute the articles "External Links".

If you don't know, Wikipedia is not a link repository. Suggestions on what to include in "External Links" can be read at External links. Thanks to your revert I did notice that I deleted the Unix commands template. Thanks for that. --71.254.13.237 23:53, 30 June 2006 (UTC)

 * One of the links you deleted was to DiffNote, which I created. It's a wrapper for diff -y, with some extra features, so it's pretty closely related to diff. Several months ago, I researched the other diff tools that were listed in the article, and many use diff as their back end. I'd agree to use that as the standard for inclusion. Right now, I can only confirm that DiffNote uses diff for its back end, so I'd like DiffNote put back.

 * I'd also like to make it easy to find alternative file comparison tools, so I'd add a link to File comparison to the See also section and mention that other tools are listed there. I'd also add something like "similar tools listed at File comparison" at the bottom of the external links section, even though it's not an external link, since that's the section that would catch people's eye if they're looking for similar tools. File comparison would then be linked three times from Diff. I obviously like usability. That's why I created DiffNote. -Barry- 01:15, 1 July 2006 (UTC)

 * Having mentioned that your revert was based on protecting your own Web site's listing would have been the better thing to do for the sake of full disclosure. This conflict of interest of yours is obviously going to cloud what you think the "standard of inclusion" will be.  This is one of the things Wikipedia advises against at External links. --71.254.13.237 22:45, 1 July 2006 (UTC)

I proposed a file comparison infobox here. -Barry- 03:28, 5 July 2006 (UTC)

Are you attempting to circumvent the removal of these external links on the Diff article by pursuing a different process at Wikipedia that will result in having these external links instead forced on every single file comparison tool page on Wikipedia? I'm sorry if that sounds like a rhetorical question, but I think you're acting quite boldly. --71.254.7.215 05:30, 5 July 2006 (UTC)

 * Links to free file comparison tools that use Diff as the back end are appropriate for this article, but I think my infobox is even better because it's easier to maintain and offers more information in a consistent, neat package. Your last two replies to me are argumentative and don't address the issue of whether my ideas will improve the article. -Barry- 06:11, 5 July 2006 (UTC)

I'm sure you think your infobox is better, but could you withdraw your proposal for the sake of it being poor form, so that we can instead wait for comments on whether these link deserve to be shown on a single page before you start placing them on multiple pages on Wikipedia? I'm sorry if I seem argumentative. I am finding it difficult to deal with an editor who has inserted themself in whether the appearance of external links should exist on a page when one of the links is of their own personal Web site, who wants to forego the current discussion on whether or not to list these external links and has gone ahead with an infobox proposal that would include such links on numerous page, a person who hasn't really acknowledged their conflict of interest, a person who ignores both precedent and suggestion provided by the Wikipedia project, and a person who copied private discussion on a user page to an article's talk page without permission. On the last, this is definitely legal act and not against Wikipedia policy, but I would have submitted my comments to the discussion page if that's where they were directed. Would you be willing to withdraw your proposal and actually let time pass so that others can comment, something you were originally interested in? I would also accept deleting both our entries in this argument back up until your propsoal on 5 July, so that people can avoid the noise we've contributed and have a better chance of engaging in the discussion. What do you think? --71.254.7.215 15:01, 5 July 2006 (UTC)

 * I was about to try a request for comments, then I noticed the third opinion page, then I decided to propose that the third opinion page be deleted rather than ask for a third opinion. I won't delete this discussion or go back to the old idea.

 * Got a response to my post on third opinion. I think I'll try RFC. Or I might just add the infobox tomorrow and leave it to you to dispute. -Barry- 19:42, 5 July 2006 (UTC)
 * And how would you see that as promoting civility and consensus? William Pietri 20:20, 5 July 2006 (UTC)

 * It doesn't, but I don't think it violates that either. The IP guy seems to mainly be questioning my motives. I don't think that should be the focus of a dispute. But if anyone here prefers the RFC or third opinion option, go ahead and try it. I tried RFC once and it didn't attract any comments. I've been through failed mediation too, and I'm currently in arbitration, so I'm familiar with the process. I prefer to avoid it, but I'll participate if someone wants to initiate it. -Barry- 20:37, 5 July 2006 (UTC)
 * I think saying that you may just ignore another user with reasonable questions is working against consensus. At least at first look, I agree with the numeric editor: the article is better without the array of links, and your personal interest in promoting your own work is indeed a reasonable concern. Per WP:VAIN and WP:AUTO, it's better to let others notice the significance of your work and add it. William Pietri 22:49, 5 July 2006 (UTC)

 * I started an RfC at Requests_for_comment/Maths%2C_science%2C_and_technology -Barry- 23:09, 5 July 2006 (UTC)
 * Great. Could you tell me about your reasoning in adding your link back without (or possibly in spite of) consensus? Thanks, William Pietri 04:15, 6 July 2006 (UTC)

 * The anonymous editor put back the link to a free, online interface to Diff, and that's basically what my link is. -Barry- 04:29, 6 July 2006 (UTC)

How is that justification for your action given that the link you added in particular is under debate here and at the center of an RfC (spawned without consensus as of late)? The link that I allegedly "put back" was mentioned in the original comment that started this whole discussion and even gave a rationale, "I did allow one Web site of note that provides output similar to using the actual Diff command." (I actually don't think it was "put back", it was kept.) Did you read my comment? If I did put it back on the second edit, I meant to keep it in my first attempt to pare down the external links. Regardless, nothing has changed that justifies adding your Web site.

This is at least the second example of both poor form and etiquette by user -Barry-. I don't really have time for this and my willingness and repeated offers to negotiate and collaborate on this is received with comments like, "I might just add the infobox tomorrow and leave it to you to dispute." --71.254.7.215 05:02, 6 July 2006 (UTC)

 * Why don't you want my link while you allowed a link to a similar tool to remain? Just because it's my tool? -Barry- 05:05, 6 July 2006 (UTC)

 * I think you adding a link to your tool is inappropriate. As WP:VAIN and WP:AUTO suggest, it's best to let others note the notability of your efforts; we are unavoidably biased about our own projects, or we wouldn't do them. William Pietri 05:52, 6 July 2006 (UTC)

 * So let me hear you or IP guy discuss whether my link should be added. There's a similar link. Why not mine too? Disallowing something for no reason is bad faith. -Barry- 05:59, 6 July 2006 (UTC)
 * I'm not disallowing it. I'm saying you shouldn't add it back after it has been removed by another editor because of the potential violation of assorted policies and guidelines. What links belong here, if any, is an interesting issue, but it's a different issue. William Pietri 06:11, 6 July 2006 (UTC)

 * I just noticed the reasoning "I did allow one Web site of note that provides output similar to using the actual Diff command." That's something, so I'll delete my link. We still have to settle the infobox issue though. -Barry- 06:13, 6 July 2006 (UTC)

unified diff example
the current diff -u example does not show at all that diff -u includes context above and below differences; for a moment, I had to wonder whether the article was showing an old version of diff -u that did not do context; but it's the example that does not allow any context as the differences are directly at both begin and end. --Habbie 01:13, 7 August 2006 (UTC)
 * Yeah. We'll need a better example. I believe I'm the originator of the example - I at first used it as a stop-gap until something better was thought up, but eventually forgot about it and that's where we are now. Shinobu 06:50, 7 August 2006 (UTC)

The example has been modified to show the context in patches, and the article now includes a "context format" output. --69.165.73.238 14:46, 15 August 2006 (UTC)

unified diff
I've majorly overhauled the 'unified diff' section... please give comments. AFAICT, the chunk size is redundant, as the patch program should be able to count the removed/added/contextual lines on its own. Anyone know otherwise? --=== Jez === 14:50, 7 September 2006 (UTC)

I assume by your second set of edits that chunk size is indeed required information:

 * If either chunk size doesn't correspond correctly with the number of actual such lines in the chunk, or any lines in the chunk are not preceded by +, -, or space, then the diff file is invalid.

I'm not so sure all the technical information on the unified diff format is required because some of your conclusions may not apply to all implementations of the patch utility. Plus, its a little bit of original research, and may not be necessary in an encyclopedia. You could try contributing it to the GNU diffutils manual (assuming your notes are based on GNU patch). It also now duplicates the summary I derived from your contributions. I'll try and fix that later. --71.161.218.87 00:51, 12 September 2006 (UTC)

I've tried my best to remove duplication. The section on unidiff now looks much shorter and even reasonable when compared to the context format. It still needs work. I imagine the file hunk header information applies to the context format and could be moved to its section. --72.92.128.194 02:24, 13 September 2006 (UTC)

The paragraphs about range information in unified format were unnecessarily complicated, invoking a symbol R for the reader to mentally rewrite into "l,s or l, as the case may be". I've changed the example to the basic l,s case and left the optional omission for the text discussion, as well as cleaning up a confusing chiasmus and making smaller readability edits. --Thnidu (talk) 18:49, 10 June 2010 (UTC)

Example error?
Is there an error on the diff examples? Specifically, the sentence "things can be added after it." never appears in the given orig/new examples.

Good eye. You may be correct. I've added it to the starting files. I don't have time, now, but maybe we can verify the examples actually correspond verbatim with eachother. (You can use diff to make sure). --71.161.214.168 21:52, 19 November 2006 (UTC)

I ran diff on the files, and the diffs appear to have the correct line number information. --75.69.52.204 12:32, 20 November 2006 (UTC)
 * You diffed the diffs? — SheeEttin {T/C} 16:21, 25 July 2007 (UTC)

interdiff
I think this article should mention interdiff, which is a program similar to diff that shows differences between diff files. Apparently it's part of patchutils by Tim Waugh. —Preceding unsigned comment added by 207.41.202.13 (talk) 16:01, 7 December 2007 (UTC)

HTML Diff and Daisy Diff
Suggest to add after Daisy Diff HTML Diff http://www.aaronsw.com/2002/diff/ —Preceding unsigned comment added by 88.149.243.200 (talk) 20:01, 15 March 2008 (UTC)

There are lots of specialized Diff tools. I just added a bunch of citation to research papers on the subject. Obviously HTML and XML are popular mentions since Wikipedia is a Web encyclopedia, but I think we need to avoid the temptation of turning the page to a directory of common day differencing tools. Such mentions are helpful to Web browsing but not to an article on Diff.

I suggest we remove most of the "free comparison tools" list in the "See also" section. --Ashawley (talk) 19:43, 12 October 2009 (UTC)

Is there a diff for WindowsXP?
Is there a diff for WindowsXP? —Preceding unsigned comment added by 71.131.2.120 (talk) 04:04, 9 June 2008 (UTC)

 * Yes. See Comparison of file comparison tools. It also lists many other very similar tools that run on WindowsXP. —Preceding unsigned comment added by 68.0.124.33 (talk) 04:14, 26 May 2009 (UTC)

Definition
The definition in the first paragraph is a little long. This part seems to make it repetetive, "or the changes made to a current file by comparing it to a former version of the same file". It would be better to have the first sentence be more concise by removing this, or making it a separate sentence.

I feel like it doesn't belong just because of its already assumed that diff compares multiple versions of the same file. --Ashawley (talk) 18:44, 14 August 2008 (UTC)

I've changed it to, "It is typically used to show the changes between a file and a former version of the same file." I'll let the Wikipedia wordsmiths sort it out from here. --Ashawley (talk) 04:12, 13 May 2009 (UTC)

Error about context format chunk ranges?
Are you sure that "the chunk ranges specify the starting line number and the number of lines the change hunk applies to in the respective file"? By looking at the example's ('diff -c') range numbers I think that these numbers represent starting line number and ending line number (not the affected lines count). What do you think? —Preceding unsigned comment added by 62.212.196.191 (talk) 01:38, 12 May 2009 (UTC)

Looks like you're right. I've changed it to, "The chunk ranges specify the starting and ending line numbers in the respective file." If I had to guess, it was probably a copy and paste typo from the section on the "unified format", where it is the case. --Ashawley (talk) 03:57, 13 May 2009 (UTC)

File addition and deletion to the patch format
The patch format discussion is missing the fact that if the "+++" line in the header refers to "/dev/null" rather than the file being edited, the patch program will interpret the hunk as file deletion (and will probably expect single hunk deleting all lines from the file. If "---" refers to "/dev/null", the patch program will interpret that as file creation (and will probably expect a single hunk adding all lines to the file). I am not sure about what will the patch program do if the "/dev/null" reference appears next to any other type of patch. —Preceding unsigned comment added by Jozue (talk • contribs) 21:59, 30 August 2009 (UTC) I also discovered that the added and removed files can be denoted by making the timestamp inside the "---" or "+++" line equal to the start of Epoch (1970-01-01 0:0:0 UTC). Also I want to tell that these discoveries are related to the Unified Diff format (not the Context Diff format), although they might be relevant to the Context Diff as well. Jozue (talk) 22:23, 30 August 2009 (UTC)

Categories
What is the justification for being in Category Formal Languages? It was added to Revision as of 15:48, 14 May 2008. I suggest deleting it. H.Marxen (talk) 20:16, 10 September 2009 (UTC)

Separate "References" section
Shouldn't there be a separate section that is separate from the footnotes? I made such an edit as, but it was reverted. --Ashawley (talk) 19:57, 12 October 2009 (UTC)

Project Xanadu reference
This surprised me. Transclusion is the inclusion of parts of documents into other documents,. I don't see the relationship with diff, which doesn't do transclusion, but takes two text files and produce the list of differences. Besides, Xanadu was a system to hold documents, not a utility; Xanadu was vaporware while diff was highly practical. My proposal is to omit this paragraph entirely. Rp (talk) 08:38, 26 March 2010 (UTC)
 * Done. Rp (talk) 12:35, 26 August 2010 (UTC)

The patch program should be aware of this.
From the article: ''As a special case, unified diff expects to work with files that end in a newline. If either file does not, unified diff will emit the special line "\ No newline at end of file" after the modifications. The patch program should be aware of this.''

Is the patch program aware of this (as it should be) or isn't it, and which is a problem that should be addressed? --221.6.44.4 (talk) 05:31, 2 June 2010 (UTC)

be careful with colors
The Usage section contains a nice, colorized example of the normal diff output, including the words "the following normal diff output", but this is misleading in that normal diff output does of course not include those helpful colors! Need to figure out some nonintrusive way of mentioning that the colors have been added for illustrative purposes but are not a feature of normal diff output. (Though perhaps this is an inspiration for yet another feature...) —Steve Summit (talk) 16:45, 21 October 2013 (UTC)
 * Good point. I added a note to explain this.Sebastian (talk) — Preceding undated comment added 09:47, 4 February 2015 (UTC)
 * I don't see colors in the example in Usage section; are we talking about dividers (i.e. "---"), which kind of seem to be in red, although I wouldn't count on it.
 * 78.162.4.244 (talk) 23:36, 19 July 2015 (UTC)
 * Yes, the first example only uses color for the dividers. Later examples (e.g. unified diff) have more colors. Sebastian (talk) 08:04, 20 July 2015 (UTC)

doug-reader source?
The source is interesting, but doesn't provide support for the statement to which it is attached, nor in fact to the previous statement (dismissing the one parenthetical remark which could be argued as relevant). If it has something relevant to the topic, that should be mentioned. TEDickey (talk) 17:19, 1 February 2015 (UTC)

early history of patch program
If someone can provide a verifiable, published source for the early release history of Larry Wall's patch program, that might improve the topic. Unsourced speculation can be removed without discussion TEDickey (talk) 12:49, 9 May 2015 (UTC)

The first mention of patch on the mod.sources archive is from January 23, 1985. However, unless there was some release announcement, that does not say anything more than that John Nelson was aware of Larry Wall's work on patch. TEDickey (talk) 13:23, 9 May 2015 (UTC)

False claims by a user who frequently missinterprets sources.
A user is trying to create the false impression that the patch utility was not published before version 1.3, but this is verifyably wrong. Here is the head from version 1.2, retrieved from a usenet archive CD:

# # # # #
 * 1) !/bin/sh
 * 1) [Laziness is the father of invention]
 * 1) Sorry the initial version was so sloppy, but I was just going on vacation
 * 2) and couldn't bear not sending it out.
 * 1) Differences from version 1.1 to 1.2:
 * 2)        Linted.
 * 3)        Malloc bug fixed.
 * 4)        Mktemp bug fixed.
 * 5)        Will now work on files larger than 32767 for machines with small ints.
 * 6)        Added a -R option for files with the new and old reversed.
 * 1) Happy patching!
 * 1) Larry Wall
 * 2) {allegra,burdvax,cbosgd,hplabs,ihnp4,sdcsvax}!sdcrdcf!lwall

I hope this person rethinks his method for giving sources and learns to understand that a reliable source may exist anywhere - the net is just one of many information sources. 09:46, 11 May 2015 (UTC)

 * If you have a source, then you can show where you found it. You have not done so. Rather, the sole content of your comments is to accuse others of lying.  TEDickey (talk) 10:19, 11 May 2015 (UTC)
 * You need to learn to correctly interpret sources and not to attack other people just because they did already found reliable sources. After some more research, patch-1.2 could even be found at google: and after two more minutes this: . Schily (talk) 11:48, 11 May 2015 (UTC)

By the way, the link cited as "November 9, 1984" does not contain that information. Lacking some verifiable reliable source, any editor can correct your edits to match the given sources TEDickey (talk) 10:22, 2 June 2015 (UTC)

 * I did not add this to the article and you just verified again that you are always acting in a non-constructive way. Given the fact that I presented the correct source, you could have corrected the article instead of adding another non-constructive comment. Schily (talk) 10:35, 2 June 2015 (UTC)

No: (a) you used the source without providing it, and (b) failed to make the suggested correction, (c) preferring to attack other editors rather than be civil. TEDickey (talk) 00:25, 3 June 2015 (UTC)
 * Please stop to attack others... I of course provided the correct verification above with the link I don't care whether you ignore this, but I care if you attack me with false claims. Schily (talk) 08:56, 3 June 2015 (UTC)

The topic as written does not incorporate this improvement which you state you have made. TEDickey (talk) 00:49, 4 June 2015 (UTC)
 * Don't misquote me! Schily (talk) 10:32, 4 June 2015 (UTC)

That's an interesting comment, indicating that you did not read my comment from 10:22, 2 June 2015 (UTC) TEDickey (talk) 00:16, 5 June 2015 (UTC)

 * I of course read your attack that was a result of not reading my original statement. Try to become a collaborative person instead of wasting other people's time. Schily (talk) 12:56, 8 June 2015 (UTC)

New material in lead
Of the new material I just added to the lead (symbol set size, Unicode issues), feel free to bend, spindle, fold, or mutilate as you wish. I think both additions improve the scope of the article, but I haven't provided citations, and I probably didn't choose the best place. This was purely a drive-by edit. — MaxEnt 20:44, 2 May 2017 (UTC)

 * It doesn't belong in the lead (lede) unless it is a summary of sourced discussion within the topic itself. TEDickey (talk) 20:55, 2 May 2017 (UTC)

Explain a/ vs. b/ path prefixes
http://lists.landley.net/pipermail/toybox-landley.net/2019-January/010049.html

tools like svn or mercurial or git will create diffs that start like: +++ a/path/to/file --- b/path/to/file

--Cgbuff (talk) 06:11, 17 January 2019 (UTC)

topicality of front-ends
vimdiff, like tkdiff is not topical because it provides a facade to an existing tool rather than being a different implementation of diff TEDickey (talk) 07:54, 28 April 2020 (UTC)
 * Actually, TEDickey's "facade" analysis was historically correct, but open source has marched on! This is especially nice if the environment is somehow missing the diff command. Happily, on 10 September 2018, with patch 8.1.0360, the xdiff library code was integrated, and is now used by default.  This native code greatly speeds the diff'ing of files or buffers. vim still provides the original method of calling out to the diff program. In a third option, a custom  user-specified diff program may be used by setting the diffexpr option.

 * Incidentally, diffpatch command still uses an external, standard, Larry Wall-derived, patch program, to apply a patch to a buffer. Mirroring the diffexpr option, patchexpr is specified to override the standard patch program.

 * Seeing the misunderstanding, I have modified and restored a vimdiff entry. Actually, re-reading the docs, vimdiff supports diff'ing two to eight files!

 * Background:

patch 8.1.0360: using an external diff program is slow and inflexible Problem:   Using an external diff program is slow and inflexible. Solution:  Include the xdiff library. (Christian Brabandt, closes #2732) Use it by default.

This problem was well known [...]. One problem why it wasn’t done earlier, was that there did not exist a good documented and simple to use C library that could be used by Vim.
 * Bundling an internal diff library with Vim

So I started working on how to improve this situation and decided to go with the xdiff library which the git developers finally settled to use. They basically had the same problem when the git vcs system was developed by Linus Torvalds. Back in around 2006 they decided to ship git with the libxdiff library, which over time got heavily modified to fit better the needs of git.

The advantage of using the same library for Vim is that, for one, the library has been tested and proven to be working well over the last 12 years. In addition, is has been tweaked and several new diff algorithms have been added, like the patience diff algorithm and histogram diff algorithm and the indent-heuristics.

 * Source: https://github.com/vim/vim/blob/master/src/diff.c#L10-L17

 * so.. you're saying that because vim now uses someone else's library rather than being a script calling a command-line implementation, then that make vim a new implementation of diff?  That sounds like you're not addressing the issue raised here. TEDickey (talk) 15:32, 2 May 2020 (UTC)

title: Talk:Diff


text:
Akvavit

Akvavit or aquavit (also akevitt in Norwegian; aquavit in English) is a distilled spirit that is principally produced in Scandinavia, where it has been produced since the 15th century. Akvavit is distilled from grain or potatoes and is flavoured with a variety of herbs. It is also popular in Northern Germany.

Akvavit gets its distinctive flavour from spices and herbs, and the dominant flavour must (according to the European Union) come from a distillate of caraway and/or dill seed. It typically contains 40% alcohol by volume, or 80 proof (U.S.). The EU has established a minimum of 37.5% ABV for akvavit to be named as such.

Etymology
The word aquavit derives from the Latin aqua vitae, "water of life." Compare the words whisky or whiskey, from Gaelic uisce beatha, which has the same meaning. Likewise, clear fruit brandy is called eau de vie (French for "water of life").

Drinking culture
Akvavit is an important part of Nordic drinking culture, where it is often drunk during festive gatherings, such as Christmas dinners and the Midsummer celebration, and as an aperitif. In Iceland, Sweden, Denmark, and Germany, aquavit is chilled and often drunk in a single gulp from a small shot glass. This is usually attributed to tradition. In Norway, it is not generally chilled, but enjoyed slowly. In Sweden, aquavit is commonly consumed immediately following a song, called a snapsvisa. The most well-known song is "Helan Går". In Finland and Sweden, aquavit consumed from a shot glass is also commonly associated with crayfish parties, which are traditionally held during late August. In Denmark, aquavit is called snaps or akvavit, and is primarily consumed in December during Christmas lunches or around Easter during Easter lunches. It is consumed year-round, though, mainly for lunches of traditional Danish dishes where beer is also always on the table. In Norway, where most aquavit is matured in oak casks, the drink is served at room temperature in tulip-shaped glasses. Aquavit arguably complements beer well, and its consumption is very often preceded by a swig of beer.

Production
Akvavit must be distilled from an agricultural base, most commonly grain or potatoes. Similarly to gin, it is flavored with botanicals. The dominant flavors must be caraway or dill, or sometimes both. Swedish Akvavit must also contain fennel in order to be labeled as such. Other common botanicals include cardamom, cumin, anise, and coriander. The Danish distillery Aalborg makes an akvavit distilled with amber, which imparts a pine-like citrusy note. The Aalborg brand is now produced in Norway by Arcus Group.

The recipes and flavours differ between brands, with each brand's unique characteristics coming from distillation methods and supporting botanicals in their blends. Un-aged Akvavit is clear, while aged Akvavit typically has a pale straw-to-golden hue, depending on how long it has been aged in oak casks (most common in Norway) or the amount of colorant used. Normally, a darker color suggests a higher age or the use of young casks, although artificial caramel colouring and infusing fruits or botanicals for color and flavor are permitted before bottling. Clear akvavit is often called taffel, meaning table aquavit. Taffel aquavit is typically aged in old casks that do not colour the finished spirit, or it is not aged at all.

Origin and traditional variants
The earliest known reference to "aquavit" is found in a 1531 letter from the Danish Lord of Bergenshus castle, Eske Bille, to Olav Engelbrektsson, the last Roman Catholic Archbishop of Norway. The letter, dated April 13 and accompanying a package, offers the archbishop "some water which is called Aqua Vite and is a help for all sort of illness which a man can have both internally and externally".

While this claim for the medicinal properties of the drink may be rather inflated, aquavit is popularly believed to ease the digestion of rich foods. In Denmark, it is traditionally associated with Christmas and Easter lunches. In Norway, it is drunk at celebrations, particularly Christmas, Easter, or May 17 (Norwegian Constitution Day). In Sweden, it is a staple of the traditional midsummer celebrations dinner, usually drunk while singing one of many drinking songs. It is usually drunk as snaps during meals, especially during the appetizer course — along with pickled herring, crayfish, lutefisk, or smoked fish. In this regard, it is popularly quipped that aquavit helps the fish swim down to the stomach.

It is also a regular in traditional Norwegian Christmas meals, including roasted rib of pork and rib of lamb (pinnekjøtt). The spices and the alcohol are said to help digest the meal, which is very rich in fat.

Among the most important brands are Løiten, Lysholm, Opland, and Simers from Norway; Aalborg and Brøndum from Denmark; and O.P. Anderson from Sweden. While the Danish and Swedish variants are normally very light in colour, most of the Norwegian brands are matured in oak casks for at least six months, and for some brands even as long as 12 years, making them generally darker in colour. While members of all three nations can be found to claim that "their" style of aquavit is the best as a matter of national pride, Swedish akvavit is typically the most renowned around the world, specifically so in the culinary scene. Whilst the Norwegian akevitt tends to have if not the most distinctive character, then at least the most overpowering flavour and deepest colour due to the aging process.

Peculiar to the Norwegian tradition are Linje Aquavits (such as "Løiten Linie" and "Lysholm Linie"). Linje Aquavit is named after the tradition of sending oak barrels of aquavit with ships from Norway to Australia and back again, thereby passing the equator ("linje") twice before being bottled. The constant movement, high humidity, and fluctuating temperature cause the spirit to extract more flavour and contribute to accelerated maturation.

Norwegian aquavit distillers Anora (formerly Arcus) carried out a test where they tried to emulate the rocking of the casks aboard the "Linje" ships while the oak barrels were subjected to the weather elements, as they would aboard a ship. The finished product was, according to Anora, far from the taste that a proper linje aquavit should have.

Therefore, to this day, boats loaded with "Linie Aquavit" set sail from Norway to Australia and back again before they are bottled and sold as part of the Norwegian Christmas traditions, but also enjoyed all year round.

Outside the Nordic countries
Aquavit was seldom produced outside of the Nordic countries, but that began to change dramatically starting around 2010, especially in the United States, and particularly in areas that have larger concentrations of people with a Nordic heritage. An exception, however, is Northern Germany, and in particular the German state of Schleswig-Holstein, which was part of Denmark until the 19th century (see History of Schleswig-Holstein) and still has a notable Danish minority. Among the most important German brands are Bommerlunder from Flensburg, Kieler Sprotte from Kiel, and Malteserkreuz. Malteserkreuz has been produced in Berlin since 1924 by a subsidiary of Sweden's Vin & Sprit AB (now Pernod Ricard), the producer of many Swedish akvavits, and can be considered a German imitation of the Nordic aquavits since it is based on an original Danish recipe. Brands from Schleswig-Holstein, however, often have a long history, comparable to their Nordic counterparts. Bommerlunder, for instance, has been made since 1760. Aquavit is also an important part of the traditional cuisine of Schleswig-Holstein. German aquavit is virtually always distilled from fermented grain and generally has an alcohol content of 38% by volume, marginally less than Scandinavian aquavits.

Psychopomp Microdistillery, in Bristol, England, started producing an aquavit (termed 'Aqvavit' due to EU regulations) in 2017. In Canada, aquavit is produced by Crosscut Distillery Sudbury; Confluence Distillery; Okanagan Spirits Craft Distillery; Island Spirits Distillery; Long Table Distillery; Spirit of York Distillery Co. in Toronto, Ontario; Newfoundland Distillery Co. in Clarke's Beach, Newfoundland; Compass Distillers in Halifax, Nova Scotia; and Sheringham Distillery on Vancouver Island, British Columbia. Many distilleries in the United States produce aquavit, especially in parts of the country with high populations of people of Nordic heritage. Examples include Colorado, Minnesota, Michigan, Wisconsin, Montana, Illinois, Oregon, New Hampshire, and Washington. The Midwest states in particular do quite well for the category and have produced numerous internationally acclaimed/award-winning brands. See List of Akvavit Producers in the United States for brand names and distilleries.

Spellings

 * Danish: Akvavit, Snaps, Brændevin or Dram
 * Norwegian: Akevitt, Brennevin or Dram
 * Swedish: Akvavit, Snaps or Kryddat brännvin
 * Dutch: Aquavit
 * English: Aquavit or Akvavit
 * Faroese: Akvavitt
 * Estonian: Akvaviit
 * Finnish: Akvaviitti
 * French: Aquavit
 * German: Aquavit, Kö(ö)m
 * Icelandic: Ákavíti
 * Italian: Acquavite
 * Polish: Okowita
 * Portuguese: Aquavit
 * Ukraine: Оковита

title: Akvavit


text:
Jimmie Dale Gilmore

Jimmie Dale Gilmore (born May 6, 1945) is an American country singer-songwriter currently living in Austin, Texas.

Life and career
Gilmore is a native of the Texas Panhandle, having been born in Amarillo and raised in Lubbock, Texas. His earliest musical influence was Hank Williams and the honky tonk brand of country music that his father played. In the 1950s, he was exposed to the emerging rock and roll of other Texans such as Roy Orbison and Lubbock native Buddy Holly, as well as to Johnny Cash and Elvis Presley, the latter two being in the line up at a concert he attended on October 15, 1955, at Lubbock's Fair Park Coliseum. He was profoundly influenced in the 1960s by The Beatles and Bob Dylan and the folk music and blues revival in that decade.

With Joe Ely and Butch Hancock, Gilmore founded The Flatlanders. The group has been performing on and off since 1972. The band's first recording project, from the early 1970s, was barely distributed. It has since been acknowledged, through Rounder's 1990 reissue (More a Legend Than a Band), as a milestone of progressive, alternative country. The three friends continued to reunite for occasional Flatlanders performances, and in May 2002, released a long-awaited follow-up album, Now Again, on New West Records.

After briefly attending Texas Tech University, Gilmore spent much of the 1970s in an ashram in Denver, Colorado, studying metaphysics with teenaged Indian guru Prem Rawat, also known as Maharaji. In the 1980s, he moved to Austin, where his first solo album, Fair & Square, was released in 1988.

In 1994, Gilmore teamed up with Willie Nelson to contribute "Crazy" to the AIDS benefit album Red Hot + Country produced by the Red Hot Organization.

Gilmore appeared as himself in Peter Bogdanovich's 1993 film The Thing Called Love, a love story about young songwriters in Nashville. He also had a small but memorable acting role in the 1998 movie The Big Lebowski. He portrayed a bowler named Smokey, an aging, emotionally "fragile" pacifist threatened with a pistol by Walter Sobchak, "The Dude" Lebowski's best friend and sidekick (John Goodman). He has also been a guest on The Tonight Show, with host Jay Leno, the Late Show with David Letterman, Garrison Keillor's A Prairie Home Companion on NPR, and the Fresh Air radio program with Terry Gross. Gilmore's son, Colin Gilmore, is also a singer–songwriter based in Austin.

Gilmore's song "Braver Newer World" is featured in the 1995 Noah Baumbach film Kicking and Screaming. In 2005, Gilmore released Come on Back, an album of songs his father loved. Gilmore said of the album, "This new album is a compilation of recordings of some old songs that my dad loved. I love them too, and it is a project very dear to me." His version of "Mack the Knife" from the album One Endless Night is on the soundtrack of Jacques Audiard's 2009 film, A Prophet (Un Prophète).

Gilmore has been nominated for three Grammys, Best Contemporary Folk Album for Spinning Around The Sun in 1993, Best Contemporary Folk Album Braver Newer World in 1996, and Best Traditional Folk Album Come On Back in 2005.

title: Jimmie Dale Gilmore


text:
User:Fro~enwiki

I want to write/re-write the Wikipedia on heavy metal. I hope to make a difference to the Wikipedia and its info about metal music. Eventually I may participate in other areas but it seems unlikely.

title: User:Fro~enwiki


text:
Talk:Napier Nomad

This a "compound cycle diesel engine" I believe.

Is there a museum in the US or UK where I can see this engine on display?

homebuilding207.178.98.48 01:00, 21 May 2007 (UTC)

---

A small mistake in the specification I think: the engine is described as "Horizontally Opposed" but the original Culverin was based on the very different Junkers "Opposed Piston" engine.

I am sure that this is just a simple mistake.

http://en.wikipedia.org/wiki/Junkers_Jumo_205

DesmondW (talk) —Preceding comment was added at 15:31, 5 December 2007 (UTC)

 * My correction withdrawn - the Nomad was indeed 12 cyliner horizontally opposed
 * DesmondW (talk) —Preceding comment was added at 16:46, 27 December 2007 (UTC)

A tricky one!
I've tried to clarify this article as it is a very complex engine, what has just occured to me is that the Naiad engine appears to have no combustion chambers, so it is no more than a giant supercharger. Need to come back and fix the text to confirm/clarify this as it is slightly wrong if this is the case. Nimbus (Cumulus nimbus floats by)    23:27, 22 August 2009 (UTC)

Nomad 1
As the article is now: < the axial compressor also drove the supercharger impeller >

but page 544 of reference 8 states, and the diagram clearly shows, that the impeller was driven by the crankshaft.

86.152.190.173 (talk) 00:36, 27 September 2011 (UTC)

 * Yes, this is one of several problems with this article. I've re-worded it a bit. The illustrations here aren't great either. The Flight article is very good, but remember that there were many variants of the Nomade during its development and even Flight were only allowed to see a couple of them, at the time. It's risky to make definitive statements about details of how the Nomad worked, because the chance is that there was always another version that had done it the other way. Andy Dingley (talk) 14:38, 27 September 2011 (UTC)

Nomad II hydraulic clutch
This was much more than a mere clutch. It was a variable-ratio transmission, namely, a Beier variable-ratio gear. 86.3.108.41 (talk) 13:41, 30 September 2011 (UTC)

180° Vee
User Aaa3-other wanted to classify this engine as a 180° Vee. Even if I appreciate the seems like reserve, I have some difficulty in imagining a 180 degrees V - and reverted immediately. Or what have I missed? Is it one more USA <==> Europe semantic issue? Jan olieslagers (talk) 20:59, 24 February 2012 (UTC)

 * There is no agreement on wiki as to what a "flat" engine is. However there is a general acceptance of 180 V and that "boxer" is only appropriate for those with the right crankshaft layout, which I don't believe includes the Nomad. Andy Dingley (talk) 21:02, 24 February 2012 (UTC)

 * Thanks for prompt and positive reply. I am however afraid it doesn't even begin to make sense with me... Flat was never in the discussion, I can see no use in entering this term. And what do you mean by the right crankshaft layout? I still fail to imagine a layout termed "180 degrees Vee", a letter V never having a 180 degrees angle in my (probably over-simple) view. ((after consulting the V engine article I can see that SOME people make a distinction, based on the sharing of crank pins by several pistons, but I have difficulty in accepting an edit war over a semantic issue)) Jan olieslagers (talk) 21:13, 24 February 2012 (UTC)

 * After more consultation, couldn't we agree to classify it as "horizontally opposed", avoiding any idle semantic argument? Jan olieslagers (talk) 21:30, 24 February 2012 (UTC)

 * hi, sry for being late, didnt expect so prompt activity. i can make all this clear: flat is every one in 180 degree bank layout where all two banks are in one plane, including vee, boxer and opposed. the broadest category. a vee is, any one where the conrods share a crankpin (angle diff=zero), regardless of bank degree, usually 60 90 180, less common 45 135 etc. a boxer is special, such a flat (180deg banks) with separate pins for every conrod AND they (pins) must be exactly 180deg apart! this makes every opposed piston move symmetrically in and out. and finally, a horizontally opposed is like this Opposed-piston engine, 2 pistons sharing a cylinder. disregarding crankshaft arrangement this is like the inside-out mirror of a boxer, both same for the purpose of balance. (rare, a VR engine is where the bank angle is usually very small (so width is much the same as an inline), and the separate crankpins' angle is the same as it would be on an inline one. made by lancia and volkswagen. comes from german V and R(eihe), for it is actually a deformed (take every second cylinder into a new, second, cylinder bank, like a V) inline made shorter, very superficially resembling a vee. but theoretically of course this can be any bank angle, and then a boxer is just a case when the bank angle is 180, that is, a flat variant of this.)

 * so seeing the above, the diff between a 180deg V and a boxer is, that on a vee, the cyl pairs are moving in unison first both left then both right, while in a boxer they cancel out each other's inertia. this intra-opposed-pair balancing is not realizable on a vee, but it can, with adequate number of pistons, can be balanced intra-bank and-or intra-block just like any inline engine. the napier nomad is an example of this. just check the image i linked File:NapierNomadCross-Section,Flight1954p1217or545.png in the article history, uploaded just this night - 2 conrods on common crankpin, 0 deg difference, ergo vee type engine. on the nomad picture, one can imagine if you rotate the shaft in your fantasy to a direction; both the pistons will move that direction as well. characteristic of the v layout. the boxer, on the other hand: File:Boxerengineanimation.gif--Aaa3-other | Talk | Contribs 23:01, 24 February 2012 (UTC)

 * re: well im not into edit war over this, but this is clearly a mechanical (balancing) (engineering coice) (etc) issue, not alinguistical/categorical... of course im avare that regardless of language or continent most people are blurring all these always, but...--Aaa3-other | Talk | Contribs 23:05, 24 February 2012 (UTC)

 * oh and dont wast too much time, imo, on reading over here on wiki, iirc last time i saw there was much chaos and incosistency over this and cant know which articles are getting it right and which arent :( on diesels for example i read orbital stupidities i planned to correct since a few weeks. the stuff is simple, only it is not cleaned up here on wiki across the whole topic. someone somewhen will do this, i hope, preferable after writing up his plan to some project page notifying others to get a consensus or whatever--Aaa3-other | Talk | Contribs 23:12, 24 February 2012 (UTC)

 * Sorry, but I'd disagree with many of your points here:
 * There is no requirement for V engines to share a crankpin. Some do, but this isn't required or implicit in the V layout itself. It's done with twins for simplicity (allowing a much simpler crankshaft), it's done with high cylinder counts to make a shorter engine with a stiffer crankcase. It's the usual choice for eight and above, it's unusual for four, and six can go either way.
 * "Opposed engines" have one cylinder per piston, with these cylinders opposite each other. These are common, especially for twins. If two pistons share a cylinder, then that's specifically termed an "opposed piston engine".
 * There are four terms for "180° V" engines: "180° V", "opposed", "flat" and "boxer". As "V engine" implies no more about an engine layout than having two cylinder banks, and "180° V" is accepted for a V at that angle, it's an acceptable term for the whole lot, including those covered by the other three terms.
 * There is much less agreement about the meaning of the other terms, whether they apply to any 180° V, or only to layouts with specific crankshaft layouts or firing orders. There is no agreement on WP about this, and not even much competent discussion of the issue by those who know any more than reading a few copies of Hot Car. They're also terms that are surprisingly hard to find good sources that explain them in a canonical form. I did the obvious thing and opened my drynamics textbooks on engine balancing, but even in these (although authoritative) there's no need felt to define their terms clearly before use - they're assumed to be clear already.
 * "Flat" sometimes (which I don't support) has implicit connotations added about the crankshaft layout being flat, not cross plane. That would then include four cylinders, but would imply that there are no flat sixes!
 * "Boxer" has a generally accepted meaning (amongst those who think it means anything more) related to piston balance by pistons moving as opposed pairs. There is argument though beyond this: do the pairs have to be in opposing cylinders? (this rules out shared crankpins). Is an engine where their pairs of balanced pistons are not in the cylinders directly opposite still boxers? I've also seen it claimed for four strokes that the pistons must not only be opposite, but must fire simultaneously - tending to a rather lumpy firing order.
 * "Opposed" is generally seen as the same as "180° V", whatever the piston and crankshaft layout, but on this page we see it being conflated with the quite distinct "opposed piston".
 * Andy Dingley (talk) 10:33, 25 February 2012 (UTC)
 * Certainly the air-cooled piston engines of Continental, Lycoming etc are usually decribed as horizontally opposed, including by sources such as Jane's All The World's Aircraft. What do the sources say about the format of the Nomad?Nigel Ish (talk) 11:44, 25 February 2012 (UTC)
 * The Nomad is described as "horizontally-opposed" in Lumsden, Caxton's "Modern High-Speed Oil Engines" and Gunston's 1954 Flight article, although in Gunston's later World Encyclopedia he terms it a flat-12. I think there's a big piece in one of Ricardo's books too, but I can't find that just at the moment. Andy Dingley (talk) 12:37, 25 February 2012 (UTC)

 * well, ok i concede to the aboves (at least as far as wiki goes) but i must then argue that the term opposed engine is at least unfortunate as it (at least in me) invariably raises the opposed piston stuff. wow ricardo wrote books? i must get them!

 * anyway, i propose the two following alts. 1)simple and safe, lets remove the cat 'boxer' and every other specials, and create 'flat', - which is then absolutely equivalent to 'opposed' (no mutter how i dont like the latter, seems really prevalent) -, which would include all 180° layouts regardless of absolutely everything else. or 2)this seems the 'right thing' but can lead to tug wars and trouble with 'hot car types' (maybe including me?, tho i wish better ;), is to create flat, and within that, create boxer and 180vee [ok no, as you say it is also 100%eq] for spec, and leave others which are either disputed or the catter just cant decide, in the root. perhaps o-pistons could get in there too as a third 2nd subcat. and for a case like this, we probably should dualput 'em in both v-12 engines and flat engines, and avoid creating numberred subcats for flats, boxers and o-pistons. or for all cases.

 * in both cases we should put the text to the flat catpage that it is also known as horizontally opposed. maybe, though i wouldnt like, the names could be switched and it (the main cat) could be called h.o. and text would mention f. --Aaa3-other | Talk | Contribs 00:18, 26 February 2012 (UTC)

 * (cat creations & edits) done. (decided to) avoided creation of numbered subcats for all cases. probably this is conclusion. --Aaa3-other | Talk | Contribs 10:35, 9 March 2012 (UTC)

 * Why have you now categorized Category:Opposed piston engines as Category:Flat engines? This is quite wrong. Andy Dingley (talk) 11:27, 9 March 2012 (UTC)

 * err... because it seemed to me flat... i mean, its 180 degree, and sor-of two banks of erm... pistons. if i cut a "real" flat in the centreline and turn the two halves inside out, it will become an o-p. but, im not at all sure or insistent on keeping it this way, just seemed a neat categorisation to me. first step. if you and/or others disagree and its wrong then of course correct it. well.... i hope some others too react; if no one then just do it in a few days, fine with me.--Aaa3-other | Talk | Contribs 12:30, 9 March 2012 (UTC)

 * p.s., only now i noticed that as the flat is - imo correctly - within the V now, the inclusion of opposed pistons is truly unfortunate.--Aaa3-other | Talk | Contribs 13:17, 9 March 2012 (UTC)

 * "Flat engine" doesn't just mean, "an engine that is flat". It carries more implicit meaning than this. Regarding opposed-piston engines as such is just plain wrong (and if you want that in wiki-bollocks-speak, then it's "uncited"). Andy Dingley (talk) 01:03, 10 March 2012 (UTC)

ok something else. i noticed you are creating very detailed subcats (inv v12 aero), including numbered subs for cyl layouts. i earlier came to the result that itd be better to avoid this as if the no-subcat way somebody navigates to the category page, he will see (thanks to the alphabethical order, and naming consistency of article titles) many relevant engines together, which would be more and more impossible, the more we do specialise the categories... the more interesting links he can found there, the better. for example, i dont want to find the royce car v12-s in a different subcat than the aero ones, and perhaps not their v8s either. also not nice if the whole german inv-v12 lineup gets unnoticed hiding away from the upright ones, on the other hand its nice to see them together. though this is obviously a question of where do we draw the line, as if the cat would grow too big... --Aaa3-other | Talk | Contribs 13:01, 9 March 2012 (UTC)

 * Then categorize them into both (or more) categories where there is some value to having them in that category. This is yet another situation where WikiMedia's slavish and simplistic assumption "Never simultaneously categorize into an ancestor category!!!" is just wrong. Andy Dingley (talk) 01:03, 10 March 2012 (UTC)

"ok", for both sub-thread -- Aaa3-other | Talk | Contribs 18:25, 10 March 2012 (UTC)

Efficiency
The article states, in a paragraph devoid of citations, that:

Thermal efficiency is given by 1-(Tx/Tp), where Tx is the exhaust temperature (any absolute scale) and Tp is the peak combustion temperature

Indeed it is, but what about Tx, and, in particular, the fraction Tx/Tp? The ratio of Tx to Tp is driven by the pressure ratio available for expansion, and this in turn is dependent on the pressure ratio on the compressor side of the engine. The Nomad was intended for economical long-range cruising (hence its name, we dare say) and had the form it did in order to achieve a high value of pressure ratio at cruise at altitude. Here the ambient pressure is low, so that high pressure ratios can be used without attaining high pressures. It was entirely beyond the state of the gas turbine art at the time to use similarly high pressure ratios. 195.194.10.62 (talk) 18:57, 4 April 2013 (UTC)

Original motivation
Thanks to 220.244.88.237 for adding this. It would be nice to improve the sourcing of this (the fuel numbers are in Ricardo, AFAIR). Any ideas on sources? There's not many for the Nomad. If only RRHT had one of their little monographs on Napier engines too!

Also the Nomad can be considered as either of two engines: as described here, a gas turbine prefixed with a high pressure ratio piston engine, or else a highly supercharged piston engine suffixed by a turbine as a turbo-compound engine. Both are contemporary themes of development around this period. There's also the 1930s work on free piston diesel engines with power output turbines.

I think we also need to expand this section to explain why the Nomad was eventually never used. The comparison with "gas turbines" is actually a comparison across a couple of generations of gas turbine, and also turboprops or turbofans. Although the low turbine inlet temperature of thee early jets was indeed a limit (and it's the effect of creep at high temperature on the turbine blades that was the early limit, not the combustor temperature), this improved a lot during the Nomad's development lifetime, such that their efficiency improved and removed the Nomad's advantage. Also the turboprop (or in practice, the Conway's turbofan) improved efficiency of gas turbine aircraft loitering at lower speeds. The Nomad's advantages over the jets just didn't last into the next generation of jets. Andy Dingley (talk) 13:45, 21 May 2013 (UTC)
 * < Why was the Nomad eventually never used? > What is the evidence that it came anywhere near certification, without which it wasn't going anywhere? (What (do we suppose) was the airframers' view of the engine's prospects?) 86.184.154.118 (talk) 00:25, 9 October 2013 (UTC)

 * The original motivation was very long range economical flight such as for maritime reconnaissance - the name 'Nomad' says it all. The engine was designed for aircraft such as the Avro Shackleton and what later became the Canadair Argus - at the time referred-to as the 'Britannia Maritime Reconnaissance'. The engine was also thought to be desirable for civilian usage where extremely long range and fuel economy was required. The Nomad could run on the cheapest fuels such as diesel - which was then, unlike today, a very cheap fuel, and so operating costs would have been - all other things being equal - much lower than for comparable engines running on 100 octane petrol - the only engines then available with the fuel economy required for transatlantic flight.

 * At the time, c1950 the then-new turboprop and turbojet had miserable fuel economy compared to piston engines, and the Nomad was developed to fill in the gap between the conventional piston engine and these types.

 * The reason for its lack of use and cancellation is simply that the airframe application's designers either chose alternative engines - such as for the Argus - or the aircraft applications themselves were cancelled - the Shackleton IV. In addition, Napier's became more interested in gas turbines such as the Nymph, Naiad, and Eland. The Nomad's chief designer BTW, was Ernest Chatterton. The E.145 Nomad gave 4,095 ehp with water injection.

 * The Nomad's problem was that it was five years too late. If it had been developed earlier it might have filled in a gap until the more economical turbojets such as the Rolls-Royce Avon came into airline service in the Comet 4. The Shackleton would also probably have been designed around it from the start, rather than the Griffon.

 * ... an article by Chatterton in a 1954 issue of Flight; quotes some 1954 UK aviation fuel prices which are; Avtur at 1 shilling & 10 pence per-gallon (pre decimalisation), 100/130 grade avgas at 2 shillings, 7 & 1/4 pence per-gal, and 115/145 grade avgas at 2 shillings and 9 pence per-gal. In contrast, diesel was 1 shilling and 8 pence per-gal.

 * A Napier Nomad 2 mounted in the outboard nacelle of a Shackleton in a 1961 issue of Flight — Preceding unsigned comment added by 2.24.215.139 (talk) 10:04, 23 September 2014 (UTC)

 * One of the best books I've read this year has been, a history of UK post-war aircraft procurement for the maritime patrol role. It's a fascinating story and a really well done book. It explains an awful lot about the procurement process, and how we ended up with the Nimrod we did. Just part of this is how the Nomad fell from favour.
 * The best aircraft for the UK maritime patrol role in the '70s and '80s would have been the Breguet Atlantic (a twin turboprop), as was bought by most of Europe. This would have been an excellent aircraft for the major role of patrolling the North Sea. But that's hindsight - back in the '50s there was no North Sea oil and the focus was on Soviet submarines crossing the GIUK gap. This was distant, so a major focus was on fast transit speeds for the aircraft in order to get on station quickly and to prolong patrol endurance. As choosing the aircraft was also a ridiculously prolonged process, by the time anything happened the turbofan engine had become credible - specifically the Rolls-Royce Spey in the Nimrod. This was fuel efficient for patrol endurance but also (compared to turboprops) it had a better transit speed for getting on stations.
 * The Nomad was still credible as an efficient patrol engine with long endurance - but none of the prop options could stand up against a turbofan for transit speed. It was the GIUK gap requirement which drove the whole patrol requirement. Andy Dingley (talk) 11:30, 22 December 2016 (UTC)

Cross-section
I notice that the cross-section has been deleted from this article, having been deleted from Commons.

It was, or could now be, copied from the 'Flight' archive. This says here:

http://www.flightglobal.com/pdfarchive/

that we all have

'100% FREE ACCESS – forever. In fact we’re positively encouraging you to link to, copy and paste from, and contribute to the development of this unique record of aerospace and aviation history'.

This suggests to me that we could legimately restore the cross-section. ..

86.148.154.31 (talk) 00:39, 16 May 2015 (UTC)

 * Free access (be it one hundred and ten percent…) doesn’t mean we obtain the right to remix, modify, re-use, or re-publish the material. It’s a read-only permission. So it’s not good enough for a Wikimedia project. Ariadacapo (talk) 05:37, 16 May 2015 (UTC)
 * No, a free licence is not required for use of images on Wikipedia (although it's required for Commons). So we can use these images easily, they just need a WP:NFC fair-use rationale. Andy Dingley (talk) 10:12, 16 May 2015 (UTC)
 * Sure. But in this case (a cross-section view of the engine in an already-illustrated article about the engine) I can’t see the rationale. This is why I made no attempt at uploading the figure here after requesting it be deleted on Commons. Ariadacapo (talk) 11:04, 16 May 2015 (UTC)
 * Of course a cross-section is valuable in a technical article on the engine, even if it's already illustrated by external photos. Andy Dingley (talk) 12:29, 16 May 2015 (UTC)
 * Absolutely! It is a valuable illustration, and an insightful drawing. But that does not guarantee it would fit within our policy for using non-free files. In the context of this article, I don’t see why it could not be replaced by a free drawing or schematic. The way I understand it, our policy is intended to cover files such as this one, i.e. items which cannot possibly or reasonably be replaced by free equivalents; not merely nice-to-have or valuable illustrations. But I might be wrong. If that drawing is uploaded to English Wikipedia under fair use rationale, I will not oppose it. Ariadacapo (talk) 14:23, 16 May 2015 (UTC)
 * So your arguments are:
 * WP requires a free licence (it doesn't)
 * There is no rationale for a cross-section if there's already an external photo (the technical details of the engine are what's notable here)
 * Some WP editor can simply re-draw one of Marsden's celebrated cross-sections for Flight, as if it were nothing. This is perhaps the UK's best known (or one of two) technical illustrator, especially for aircraft subjects. Yet when WP is given permission by Flight themselves to use it, you decide that it can't be used because "it could reasonably be re-drawn" by some other editor, who wouldn't even have access to the engine drawings!
 * You're not really here for the content work, are you? But my, what fun that bureaucracy is! Andy Dingley (talk) 14:47, 16 May 2015 (UTC)
 * Sure, you are correct, and I am wrong. Never mind what I wrote here. Ariadacapo (talk) 15:12, 16 May 2015 (UTC)

title: Talk:Napier Nomad


text:
C News

C News is a news server package, written by Geoff Collyer, assisted by Henry Spencer, at the University of Toronto as a replacement for B News. It was presented at the Winter 1987 USENIX conference in Washington, D.C.

Functionally, the operation of C News is very much like that of B News. One major difference was that C News was written with portability in mind. It ran on many variants of Unix and even MS-DOS. The relaynews program that handled article filing and feeding was carefully optimized and designed to process articles in batches, while B News processed one article per program invocation. The authors claimed that relaynews could process articles 19 times as quickly as B News.

In 1992, Collyer gave C News a new index facility called NOV (or News Overview). This allowed newsreaders to rapidly retrieve header and threading information with relatively little load on the server. Virtually all news servers continue to use this method in the form of the NNTP XOVER command. Development of C News stopped about 1995, and the package was largely superseded by INN.

title: C News


text:
User:Sputicus

Hey, its great to be here. Thanks for coming.

title: User:Sputicus


text:
Aquavit

Aquavit may refer to:

 * Aqua vitae, Latin for "water of life", a concentrated alcoholic distillate
 * Akvavit, a Scandinavian distilled beverage
 * Okovita, a historic Polish-Ukrainian term for an alcoholic drink related to vodka
 * Restaurant Aquavit, a Scandinavian restaurant in New York

title: Aquavit


text:
Henry Spencer

Henry Spencer (born 1955) is a Canadian computer programmer and space enthusiast. He wrote "regex", a widely used software library for regular expressions, and co-wrote C News, a Usenet server program. He also wrote The Ten Commandments for C Programmers. He is coauthor, with David Lawrence, of the book Managing Usenet. While working at the University of Toronto he ran the first active Usenet site outside the U.S., starting in 1981. His records from that period were eventually acquired by Google to provide an archive of Usenet in the 1980s.

The first international Usenet site was run in Ottawa, in 1981; however, it is generally not remembered, as it served merely as a read-only medium. Later in 1981, Spencer acquired a Usenet feed from Duke University, and brought "utzoo" online; the earliest public archives of Usenet date from May 1981 as a result.

The small size of Usenet in its youthful days, and Spencer's early involvement, made him a well-recognised participant; this is commemorated in Vernor Vinge's 1992 novel A Fire Upon the Deep. The novel featured an interstellar communications medium remarkably similar to Usenet, down to the author including spurious message headers; one of the characters who appeared solely through postings to this was modeled on Spencer (and, slightly obliquely, named for him).

He is also credited with the claim that "Those who do not understand Unix are condemned to reinvent it, poorly."

Preserving Usenet
In mid-December 2001, Google unveiled its improved Usenet archives, which now go more than a decade deeper into the Internet's past than did the millions of posts that the company had originally acquired when it bought an existing archive called Deja News.

Between 1981 and 1991, while running the zoology department's computer system at the University of Toronto, Spencer copied more than 2 million Usenet messages onto magnetic tapes. The 141 tapes wound up at the University of Western Ontario, where Google's Michael Schmidt tracked them down and, with the help of David Wiseman and others, got them transferred onto disks and into Google's archives.

Free software contributions
Henry Spencer helped Geoff Collyer write C News in 1987.

At around the same time he wrote a non-proprietary replacement for, the Unix library for handling regular expressions, and made it freely available; his API followed that of Eighth Edition Research Unix. Spencer's library has been used in many software packages, including Tcl, MySQL (prior to MySQL 8.0.4), and PostgreSQL, as well as being adapted for others, including early versions of Perl. Circa 1993, Spencer donated a second version of his RE library to 4.4BSD, following the POSIX standard for regular expressions.

Spencer was technical lead on the FreeS/WAN project, implementing an IPsec cryptographic protocol stack for Linux.

He also wrote 'aaa' (Amazing Awk Assembler), which is one of the longest and most complex programs ever written in the awk programming language.

He also developed a 4 point font used by entomologists in labeling pinned insect specimens.

Space
Spencer is a founding member of the Canadian Space Society, and has served on its board of directors several times since 1984. He did mission analysis (planning of launch and orbits) for the CSS's Canadian Solar Sail project (now defunct), and was Software Architect for MOST, a Canadian science microsatellite dedicated to studying variable light from stars and extrasolar planets launched by Eurockot in 2003. The asteroid 117329 Spencer is named in his honour.

He is a highly regarded space enthusiast, and is a familiar and respected presence on several space forums on Usenet and the Internet. From 1983 to 2007 Spencer posted over 34,000 messages to the sci.space.* newsgroups. His knowledge of space history and technology is such that the "I Corrected Henry Spencer" virtual T-shirt award was created as a reward for anyone who can catch him in an error of fact.

title: Henry Spencer


text: Talk:Battle of Bennington

title: Talk:Battle of Bennington