IGS. Short history

The first and most long lasting Go Server is of course IGS, the Internet go Server. This started in February 1992 at the Univesity of New Mexico and moved around the USA before heading to Korea and its current home of Japan. It is currently owned by NKB Inc and promoted as IGS-PandaNet. It has three official clients: gGo, glGo and Panda-IGS (originally known as the PandaEgg). It has probably the largest multi-national usage and there are hundreds of players on it at any time. They also run a members' magazine and teaching service, and broadcast top tournament games live.

Source: http://www.britgo.org/