This package is based on the package go written in 1991 by Hanna Kołodziejska which provides typesetting facilities for Go games and positions. Although igo contains roughly the same commands as the original package and uses the fonts created by Kołodziejska, it has been improved in a number of ways. It uses command names less likely to conflict with standard AMS packages. It allows different board sizes to be used. It understands a standardized notation for board coordinates. And it provides a facility to work on more than one board. Moreover, a few commands were reworked to define positions or game sequences more conveniently.