KGS Go Server
The KGS Go Server, known until 2006 as the Kiseido Go Server, is a game server first developed in 1999 and 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. A list of the top 100 players (sorted by KGS calculated rank) is regularly updated and maintained.
The KGS Go Server is distinguished by a kibitz culture. Kibitzes are common and popular in high-level games, and may include off-topic discussions though this is discouraged by the administrators. The two players cannot see kibitzers' comments until after the game.
There are three client programs provided to connect to KGS. CGoban 3 is for normal use, on any system that supports Java (software platform). It supports 30 different languages, and can also be used as an SGF file editor/viewer. An applet version of CGoban3 is available, but lacks the ability to save files to the users computer and cannot be used as an SGF file editor/viewer. kgsGtp is another java program, for use by Go-playing programs. KGS Client for Android is for mobile phones that use the Android system; it currently supports several languages, but not as many as CGoban 3.
KGS allows games on any size board, including the 19x19, 13x13 & 9x9 boards. Games can be rated, free, teaching or pair games.