- 3Dc (C, GPL-2.0, mature, inactive since 2000)
- British Bingo (JavaScript, GPL-3.0, mature)
- Catan Dice Game (Java, GPL-3.0, mature)
- Chess3D (JavaScript, Python, GPL-3.0, mature, inactive since 2016)
- Crosswords (Java, GPL-2.0, mature)
- Deer Portal (C++, zlib, beta)
- Domination (Java, GPL-3.0, mature)
- DreamChess (C, GPL-3.0, beta)
- Foursies (Elm, JavaScript, GPL-3.0, mature, inactive since 2016)
- glParchis (Python, GPL-3.0, mature)
- GNU Go (C, GPL-3.0, mature, inactive since 2011)
- Hnefatafl (C, ISC, beta, inactive since 2014)
- Holtz (C++, GPL-2.0, mature)
- Ithaka Board Game (Java, GPL-3.0, mature)
- JSettlers (Java, GPL-3.0, mature)
- Magic Gardeners Tournament (Python, GPL-2.0, beta, inactive since 2007)
- OGS Mahjong (C++, GPL-3.0, mature, inactive since 2016)
- Open Legend RPG (None, Custom, mature)
- Pachi (C, Python, GPL-2.0, mature)
- Pasang Emas (Vala, GPL-3.0, mature)
- Pentobi (C++, GPL-3.0, mature)
- Pioneers (C, GPL-2.0, mature)
- Quatter (C++, GPL-2.0, mature, inactive since 2018)
- Scrabble3D (Pascal, GPL-3.0, mature, inactive since 2015)
- The Bub's Brothers (Python, C, MIT, mature, inactive since 2013)
- VASSAL (Java, LGPL-2.1, mature)