Andrew "Tridge" Tridgell (born 28 February 1967) is an Australian

computer programmer A programmer, computer programmer or coder is an author of computer source code someone with skill in computer programming. The professional titles ''software developer'' and ''software engineer'' are used for jobs that require a progr ...

. He is the author of and a contributor to the

Samba Samba () is a broad term for many of the rhythms that compose the better known Brazilian music genres that originated in the Afro-Brazilians, Afro Brazilian communities of Bahia in the late 19th century and early 20th century, It is a name or ...

file server In computing, a file server (or fileserver) is a computer attached to a network that provides a location for shared disk access, i.e. storage of computer files (such as text, image, sound, video) that can be accessed by workstations within a co ...

, and co-inventor of the

rsync rsync (remote sync) is a utility for transferring and synchronizing files between a computer and a storage drive and across networked computers by comparing the modification times and sizes of files. It is commonly found on Unix-like opera ...

algorithm. He has analysed complex

proprietary protocol In telecommunications, a proprietary protocol is a communications protocol owned by a single organization or individual. Intellectual property rights and enforcement Ownership by a single organization gives the owner the ability to place restricti ...

s and algorithms, to allow compatible

free and open source software Free and open-source software (FOSS) is software available under a Software license, license that grants users the right to use, modify, and distribute the software modified or not to everyone free of charge. FOSS is an inclusive umbrella term ...

implementations.

Projects

Tridgell was a major developer of the Samba software, analyzing the

Server Message Block Server Message Block (SMB) is a communication protocol used to share files, printers, serial ports, and miscellaneous communications between nodes on a network. On Microsoft Windows, the SMB implementation consists of two vaguely named Windows ...

protocol used for workgroup and network file sharing by

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

products. He developed th

hierarchical memory allocator, originally as part of Samba. For his PhD dissertation, he co-developed

, including the rsync algorithm, a highly efficient

file transfer File transfer is the transmission of a computer file through a communication channel from one computer system to another. Typically, file transfer is mediated by a communications protocol. In the history of computing, numerous file transfer protoc ...

and synchronisation tool. He was also the original author of rzip, which uses a similar algorithm to rsync. He developed spamsum, based on

locality-sensitive hashing In computer science, locality-sensitive hashing (LSH) is a fuzzy hashing technique that hashes similar input items into the same "buckets" with high probability. (The number of buckets is much smaller than the universe of possible input items.) Si ...

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

chess engine In computer chess, a chess engine is a computer program that analyzes chess or List of chess variants, chess variant positions, and generates a move or list of moves that it regards as strongest. A chess software engine, engine is usually a Front ...

. Tridgell was also a leader in hacking the

TiVo TiVo ( ) is a digital video recorder (DVR) developed and marketed by Xperi (previously by TiVo Corporation and TiVo Inc.) and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose fea ...

to make it work in Australia, which uses the

PAL Phase Alternating Line (PAL) is a color encoding system for analog television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...

video format. In April 2005, Tridgell tried to produce free software (now known as SourcePuller) that interoperated with the

BitKeeper BitKeeper is a discontinued software tool for distributed revision control of computer source code. Originally developed as proprietary software by BitMover Inc., a privately held company based in Los Gatos, California, it was released as open-sou ...

source code repository. This was cited as the reason that BitMover revoked a license allowing

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

developers free use of their BitKeeper product.

Linus Torvalds Linus Benedict Torvalds ( , ; born 28 December 1969) is a Finnish software engineer who is the creator and lead developer of the Linux kernel. He also created the distributed version control system Git. He was honored, along with Shinya Yam ...

, 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. Tridgell claimed his analysis started with simply

telnet Telnet (sometimes stylized TELNET) is a client-server application protocol that provides access to virtual terminals of remote systems on local area networks or the Internet. It is a protocol for bidirectional 8-bit communications. Its main ...

ing to a BitKeeper server and typing help. In 2011 Tridgell became involved with the software development of ArduPilot Mega, an open source Arduino-based UAV controller board, working on an entry with CanberraUAV for the UAV Challenge Outback Rescue.

Academic achievements

Tridgell completed a PhD at the Computer Sciences Laboratory of the

Australian National University The Australian National University (ANU) is a public university, public research university and member of the Group of Eight (Australian universities), Group of Eight, located in Canberra, the capital of Australia. Its main campus in Acton, A ...

. His original doctorate work was in the area of

speech recognition Speech recognition is an interdisciplinary subfield of computer science and computational linguistics that develops methodologies and technologies that enable the recognition and translation of spoken language into text by computers. It is also ...

but was never completed. His submitted dissertation 'Efficient Algorithms for Sorting and Synchronization' was based on his work on the

algorithm.

Awards and honours

* In October 2003, The Bulletin magazine judged Tridgell to be Australia's smartest

Information and Communications Technology Information and communications technology (ICT) is an extensional term for information technology (IT) that stresses the role of unified communications and the integration of telecommunications (telephone lines and wireless signals) and computer ...

person. * In July 2008, Tridgell was named "Best Interoperator" at the Google–O'Reilly Open Source Awards, for his work on

and

. *Tridgell (along with Jeremy Allison and Volker Lendecke) has been called a "

guru Guru ( ; International Alphabet of Sanskrit Transliteration, IAST: ''guru'') is a Sanskrit term for a "mentor, guide, expert, or master" of certain knowledge or field. In pan-Indian religions, Indian traditions, a guru is more than a teacher: tr ...

in its traditional Indian meaning" by IT writer, Sam Varghese. * On 11 December 2018, Tridgell was awarded the degree of Doctor of Science (

Honoris Causa An honorary degree is an academic degree for which a university (or other degree-awarding institution) has waived all of the usual requirements. It is also known by the Latin phrases ''honoris causa'' ("for the sake of the honour") or ''ad hono ...

) by the Australian National University, for authoring Samba, co-inventing rsync; and contributions to free and open source software. * On 26 January 2020, Tridgell was awarded the Medal (OAM) of the

Order of Australia The Order of Australia is an Australian honours and awards system, Australian honour that recognises Australian citizens and other persons for outstanding achievement and service. It was established on 14 February 1975 by Elizabeth II, Monarch ...

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

, ArduPilot, MAVProxy as well as teaching at the

References

External links

Andrew Tridgell's websiteNewer Personal Website

Andrew Tridgell's "Junk Code" collection

Efficient Algorithms for Sorting and Synchronization (PhD thesis)
– (406kB PDF)
Active Directory in Samba 4 'an old story'

FOSS folk who make us proud

Patent Defence for Free Software
January 2010 presentation transcript {{DEFAULTSORT:Tridgell, Andrew Australian computer programmers Free software programmers IBM employees 1967 births Living people People from the Australian Capital Territory University of Sydney alumni Australian National University alumni Geeknet People educated at Barker College Recipients of the Medal of the Order of Australia