Minetest: A Open-World Voxel Sandbox Game

Minetest is an open-source, open-world, voxel-based sandbox game engine with expansive support for mods. Version 5.2, along with several mods, are now available in the Fienix software repository. 

Fienix Open-Source Gaming Series:  Minetest Video
Minetest Website

 

Darkplaces

Darkplaces is a significantly modified and enhanced version of the id Tech 2 game engine. It features an OpenGL renderer, support for shaders, normal mapping, deluxemaps, bumpmapping, realtime lighting, bloom lighting, model interpolation, and many other effects and enhancements. Supported games include Quake, Nexuiz, Xonotic, and RetroBlazer.  
I'm pleased to announce that Darkplaces engine, Quake-HD-Remix (requires game data), Nexuiz, Xonotic, and RetroBlazer are now available in the Fienix software repository. 

Quake-HD-Remix

Quake-HD-Remix

RetroBlazer

AlephOne

AlephOne is the open-source continuation of Bungie's Marathon game engine. In addition to playing the Marathon Trilogy, AlephOne also plays several third-party games built for this game engine. AlephOne features several enhancements over the original engine, including OpenGL rendering, support for high-resolution graphics and texture packs, plugins, 3D models, Lua scripting, and internet multiplayer. 
In 2005 Bungie authorized the release of the full original Marathon Trilogy for no-charge online distribution. 
I'm pleased to announce that the AlephOne game engine, as well as the Marathon Trilogy, and several third-party games are now available on the Fienix software repository.