Arianne is an engine to develop multiplayer online games like Stendhal
Java Settlers
A synchronisation component for p5.js
3D .NET engine for Windows, Linux, Mac
Free strategy browsergame engine.
Educational framework for OpenGLES, OpenCL and OpenAL
Modular Gaming Open Source Persistent Browser Based Game Framework
Open source network game service
C-Lesh is a game programming language for 2D games.
Atlarius is no longer under development.
Andruill Engine is a GMS (Game Management System) written in PHP.