GNU Go is a free software

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

 program by the Free Software Foundation

Free Software Foundation

The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...

 that plays Go

Go (board game)

Go , is an ancient board game for two players that originated in China more than 2,000 years ago...

. Its source code

Source code

In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...

 is quite portable, and can be easily compiled for GNU

GNU

GNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...

/Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, as well as other Unix

Unix

Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

-like systems, Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 and Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

; port

Porting

In computer science, porting is the process of adapting software so that an executable program can be created for a computing environment that is different from the one for which it was originally designed...

s exist for other platforms.

The program plays Go against the user, at about 5 to 7 kyu

Go ranks and ratings

Skill in the traditional board game Go is measured by a number of different national, regional and online ranking and rating systems. Traditionally, go rankings have been measured using a system of dan and kyu ranks...

 strength on the 9x9 board. Multiple board sizes are supported, from 5×5 to 19×19.

Strength

At this level of performance, GnuGo was between six and seven stones weaker than the top commercial programs on good hardware as of early 2009, but comparable in strength to the strongest programs not using Monte Carlo method

Monte Carlo method

Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in computer simulations of physical and mathematical systems...

s. It did well at many computer Go

Computer Go

Computer Go is the field of artificial intelligence dedicated to creating a computer program that plays Go, a traditional board game.-Performance:...

 tournaments. For instance, it took the gold medal at the 2003 and 2006 Computer Olympiad

Computer Olympiad

The Computer Olympiads are a multi-games event taking place every year in which computer programs compete against each other. The majority of the games are board games but other games such as Bridge take place as well...

 and second place at the 2006 Gifu Challenge.

Protocols

Although ASCII

ASCII

The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...

-based, GNU Go supports two protocols — the Go Modem Protocol and the Go Text Protocol

Go Text Protocol

The Go Text Protocol is a protocol used by several engines for playing the board game Go on the computer. GTP version 1 has been implemented in GNU Go 3.0.0 but the protocol lacks a proper specification. Currently used version is GTP 2, but only a draft exists, not a final specification.-External...

 — by which GUI

Gui

Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...

s can interface with it to give a graphical display. Several such GUI

Gui

Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...

s exist. GTP also allows it to play online on Go servers (through the use of bridge programs), and copies can be found running on NNGS, KGS

KGS Go Server

The KGS Go Server, known until 2006 as the Kiseido Go Server, is a game server first developed in 1999 and firmly established in 2000 for people to play Go. The system was developed by William M. Shubert and its code is now written entirely in Java...

, and probably others.

Versions

The current (stable) version of GNU Go is 3.8. The latest experimental release was 3.7.13. There is also an experimental feature for using Monte Carlo methods for 9x9 board play.

A version called Pocket GNU Go, based on GNU Go 2.6, is available for the Windows CE

Windows CE

Microsoft Windows CE is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows...

 operating system (Pocket PC

Pocket PC

A Pocket PC is also known by Microsoft as a 'Windows Mobile Classic device'. It is a hardware specification for a handheld-sized computer, personal digital assistant , that runs the Microsoft 'Windows Mobile Classic' operating system...

). Versions based on the much weaker 1.2 engine also exist for the Game Boy Advance

Game Boy Advance

The is a 32-bit handheld video game console developed, manufactured, and marketed by Nintendo. It is the successor to the Game Boy Color. It was released in Japan on March 21, 2001; in North America on June 11, 2001; in Australia and Europe on June 22, 2001; and in the People's Republic of China...

 and Palm Pilot.

See also

• Go
• Go software
  Go software
  There is an abundance of go software available to support players of the game of Go. This includes software programs that play Go themselves, programs that can be used to view and/or edit game records and diagrams, programs that allow the user to search for patterns in the games of strong players...
  
  
• Computer Go
  Computer Go
  Computer Go is the field of artificial intelligence dedicated to creating a computer program that plays Go, a traditional board game.-Performance:...
  
  
• GNU Chess
  GNU Chess
  GNU Chess is a computer program which plays a full game of chess against a human or other computer program.GNU Chess is one of the oldest computer chess programs for Unix-based computers and one of the earliest available with full source code....
  
  
• GNU Robots