Arianne is an engine to develop multiplayer online games like Stendhal
Game engine supporting many 3D/2D formats and graphic effects
Orx: Portable Game Engine
JavaScript framework to build game engines, games, emulators and apps
Old-school 2D game engine
A Complete WebGPU Game Engine for Browser & Desktop Arcade Oriented
Java Settlers
The imaginary eight-bit machine
A cross platform Lua based game engine
8-bit Graphical API for Java
A complete web framework to create online Fighting Fantasy adventures
Portable game engine with main focus on point-and-click adventures
X3D Prototypes for the SMUOS Component
Build Cross-platform Applications
An environment to develop games based on a rectangular board
Asphyre is a cross-platform framework for Delphi and FreePascal.
3D .NET engine for Windows, Linux, Mac
Flexible and easy-to-use 2d game engine