OGS - Play go/weiqi/baduk online
Chess Tempo Database - Chess Tempo Database gives you a library of more than 2 million searchable chess games.
qGo - Go is an ancient boardgame, very common in Japan, China and Korea.
DecodeChess - AI chess tutor and analysis
KaTrain - Improve your go by training with KataGo.
ChessPad - ChessPad is a feature-rich chess game viewer and PGN file editor available for Windows.