Andrew Tridgell

Tridgell was a major developer of the Samba software, analyzing the Server Message Block protocol used for workgroup and network file sharing by Microsoft Windows products. He developed the [https://talloc.samba.org/talloc/doc/html/index.html {{not a typo|talloc}}] hierarchical memory allocator, originally as part of Samba.

For his PhD dissertation, he co-developed rsync, including the rsync algorithm, a highly efficient file transfer and synchronisation tool. He was also the original author of rzip, which uses a similar algorithm to rsync. He developed spamsum,{{clarify|and what would that be?|date=June 2016}} based on locality-sensitive hashing algorithms.{{cite journal|author=Jesse Kornblum|title=Identifying almost identical files using context triggered piecewise hashing|url=http://dfrws.org/2006/proceedings/12-Kornblum.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://dfrws.org/2006/proceedings/12-Kornblum.pdf |archive-date=2022-10-09 |url-status=live|journal=DFRWS|year=2006|access-date=23 February 2014}}

He is the author of KnightCap, a reinforcement-learning based chess engine.

Tridgell was also a leader in hacking the TiVo to make it work in Australia, which uses the PAL video format.{{Cite web |url=http://www.samba.org/~tridge/tivo-ethernet/ |title=TiVo Ethernet |first=Andrew |last=Tridgell |access-date=17 August 2012 |archive-date=14 January 2012 |archive-url=https://web.archive.org/web/20120114183142/http://www.samba.org/~tridge/tivo-ethernet/ |url-status=dead }}

In April 2005, Tridgell tried to produce free software (now known as SourcePuller) that interoperated with the BitKeeper source code repository. This was cited as the reason that BitMover revoked a license allowing Linux developers free use of their BitKeeper product.[https://lwn.net/Articles/169178/ git [LWN.net]] Linus Torvalds, the creator of the Linux kernel, and Tridgell were thus involved in a public debate about the events, in which Tridgell stated that, not having bought or owned BitKeeper – and thus having never agreed to its license – he could not violate it, and was analyzing the protocol ethically, as he had done with Samba. Tridgell's involvement in the project resulted in Torvalds accusing him of playing dirty tricks with BitKeeper.{{Cite news |url=https://www.theregister.co.uk/2005/04/14/torvalds_attacks_tridgell/ |title=Torvalds knifes Tridgell: Kernel source row turns nasty |first= Andrew |last=Orlowski |date=14 April 2005 |work=The Register}} Tridgell claimed his analysis started with simply telneting to a BitKeeper server and typing help.{{Cite web |url=http://www.groklaw.net/articlebasic.php?story=20050421023821174 |title=Groklaw – Tridge Speaks |access-date=5 September 2007 |archive-url=https://web.archive.org/web/20110527150705/http://www.groklaw.net/articlebasic.php?story=20050421023821174 |archive-date=27 May 2011 |url-status=dead }}

In 2011 Tridgell became involved with the software development of ArduPilot Mega,[http://diydrones.com/profile/AndrewTridgell Andrew Tridgell's Page] {{Webarchive|url=https://web.archive.org/web/20120414011835/http://diydrones.com/profile/AndrewTridgell |date=14 April 2012 }}. DIY Drones. Retrieved on 19 September 2013. an open source Arduino-based UAV controller board, working on an entry with CanberraUAV{{Cite web |date=2018-12-03 |title=CanberraUAV – Open Source Civilian UAV Development |url=http://www.canberrauav.com/ |access-date=2024-03-31 |archive-url=https://web.archive.org/web/20181203100833/http://www.canberrauav.com/ |archive-date=3 December 2018 }} for the UAV Challenge Outback Rescue.[http://www.uavoutbackchallenge.com.au/ UAV Challenge – Outback Rescue 2013 – Home] {{webarchive|url=https://web.archive.org/web/20120210145124/http://www.uavoutbackchallenge.com.au/ |date=10 February 2012 }}. Retrieved on 19 September 2013.

Tridgell completed a PhD at the Computer Sciences Laboratory of the Australian National University. His original doctorate work was in the area of speech recognition but was never completed. His submitted dissertation 'Efficient Algorithms for Sorting and Synchronization' was based on his work on the rsync algorithm.{{Cite web|url=https://www.genealogy.math.ndsu.nodak.edu/id.php?id=59310|title=Andrew Tridgell - The Mathematics Genealogy Project|website=www.genealogy.math.ndsu.nodak.edu|access-date=2017-12-11}}

• In October 2003, The Bulletin magazine judged Tridgell to be Australia's smartest Information and Communications Technology person.[http://sites.ninemsn.com.au/smart100/default.asp The Bulletin Smart 100] {{webarchive |url=https://web.archive.org/web/20070318022419/http://sites.ninemsn.com.au/smart100/default.asp |date=18 March 2007 }}[http://bulletin.ninemsn.com.au/article.aspx?id=135066 The Bulletin publishes for the last time] {{webarchive|url=https://web.archive.org/web/20070509095038/http://bulletin.ninemsn.com.au/article.aspx?id=135066 |date=9 May 2007 }}
• In July 2008, Tridgell was named "Best Interoperator" at the Google–O'Reilly Open Source Awards, for his work on Samba and rsync.[http://google-opensource.blogspot.com/2008/07/and-winners-of-2008-google-oreilly-open.html Google Open Source Blog: ... and the winners of the 2008 Google-O'Reilly Open Source Awards are]
• Tridgell (along with Jeremy Allison and Volker Lendecke) has been called a "guru in its traditional Indian meaning" by IT writer, Sam Varghese.[http://www.itwire.com/opinion-and-analysis/open-sauce/15896-foss-folk-who-make-us-proud FOSS folk who make us proud], Sam Varghese, iTWire, 2007-12-25, accessed 27 September 2009
• On 11 December 2018, Tridgell was awarded the degree of Doctor of Science (Honoris Causa) by the Australian National University, for authoring Samba, co-inventing rsync; and contributions to free and open source software.{{Cite web|url=https://livestream.com/reedgrad/111218AN2/videos/184628443|title=ANU Graduation Ceremony 1 - from ANU Graduation Ceremony 2|website=Livestream|access-date=2018-12-11}}{{Cite web|url=https://www.anu.edu.au/news/all-news/honorary-degree-dr-andrew-tridgell|title=ANU Honorary degree: Dr Andrew Tridgell|date=13 December 2018}}
• On 26 January 2020, Tridgell was awarded the Medal (OAM) of the Order of Australia in the General Division for service to Information Technology. The biographical notes for the award noted his contributions to software development and education including his work on rsync, Samba, ArduPilot, MAVProxy as well as teaching at the Australian National University.{{Cite web|url=https://www.gg.gov.au/australian-honours-and-awardsaustralian-honours-lists/australia-day-2020-honours-list|title=Australia Day 2020 Honours List}}

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{{Portal|Free and open-source software}}

• [http://www.samba.org/~tridge/ Andrew Tridgell's website], [https://tridgell.net/tridge/ Newer Personal Website]
• [https://github.com/tridge/junkcode Andrew Tridgell's "Junk Code" collection]
• [http://samba.org/~tridge/phd_thesis.pdf Efficient Algorithms for Sorting and Synchronization (PhD thesis)] – (406kB PDF)
• [http://www.itwire.com/opinion-and-analysis/open-sauce/22773-lca2009-active-directory-in-samba-4-an-old-story Active Directory in Samba 4 'an old story']
• [http://www.itwire.com/opinion-and-analysis/open-sauce/15896-foss-folk-who-make-us-proud FOSS folk who make us proud]
• [http://news.swpat.org/2010/03/transcript-tridgell-patents/ Patent Defence for Free Software], January 2010 presentation transcript

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Category:Australian computer programmers

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