Arianne is an engine to develop multiplayer online games like Stendhal
A fun realistic multiplayer free-and-open-source first-person-shooter!
Chess Database and PGN viewer
Opengate is a Jumpgate remake
The ultimate cataloguer
The multiplayer game engine
Java Settlers
Teach your students how to figure out tricky texts in any language.
Playing Go with web-based turn-based Go server
oGame-like browser space realtime strategy game based on xNova
Multiplatform Multiemulator Frontend
A console/ncurses chess engine frontend and PGN editor.
scriptable game engine with built-in support for 2D graphics and sound
starrydb is game server engine
Extensive Java chess database libraries.
3D .NET engine for Windows, Linux, Mac
An open-source MasterMind clone
A 3D game engine in java.
plugin-based RPG manager in C++ and Qt5
Next generation web chess club