Heaps : Haxe Game Framework

AGS editor and engine source code

Anura Engine

Aquaria open source, forked from icculus.org due to inactivity. Has many enhancements compared to the original version.

The latest version of the Inform 6 compiler, used for generating interactive fiction games.

A real time 3D engine.

The Lua programming language with CMake based build

The Ren'Py Visual Novel Engine

The 2013 edition of the Source SDK

Quake GPL Source Release

System Shock (PowerMac version / Official GPL Release)

The source code to VVVVVV! https://thelettervsixtim.es/

A music sequencer using DirectX and which is not depend on MIDI device.

The core software distribution for the Inform 7 programming language.

This is the source code for the original Microsoft 3D Movie Maker released in 1995. This is not supported software.

Argonaut Blazing Render (BRender) 3D engine

Modernized fork of BRender