Game engine supporting many 3D/2D formats and graphic effects
Cross-platform 2D and 3D game engine
An isometric arcade-style game of skill, puzzles and exploration
Free and Open Game Programming Language for Windows and GNU/Linux
Ze Text Adventure game Builder : Create as you play !
IRB is a game creation toolkit
JavaScript framework to build game engines, games, emulators and apps
3D .NET engine for Windows, Linux, Mac
Orx: Portable Game Engine
Java Settlers
INSTEAD - Simple Text Adventure Interpreter.
A lightweight HTML5 Game Engine
PyCAPGE - Python Classic Adventure Point and Click Game Engine
Processes dialogue text files exported by the Bethesda Softworks SDK
Open Source Virtual World and MMOG Development Platform
SDK for Resident Evil Games