Blueshift is a cross-platform 3D game engine implemented in C++
Legandary Story of the Zarakite
Multidocument automation by templates - for sphinx, mkdocs, epydoc ...
Free MMORPG
Portable game engine with main focus on point-and-click adventures
3D-Accelerated open-source DOOM engine
Dizzy Omega - sequel of Dizzy Y game
3D driving simulation based on Open Dynamics Engine
Vivid Engine 2 is an open source 3D Engine coded using C# and C++.
3D graphics engine. Little progress; project cancelled.
Bot for id Software's Wolfenstein 3D
A snarky 2D management game about building and running a dungeon.
A 3D simulator game where you can drive, fly, and sail
Web application for displaying in 3D a Survivalcraft world