Arx Libertatis is a cross-platform, open source port of Arx Fatalis, a 2002 first-person role-playing game developed by Arkane Studios. Arx Fatalis features crafting, melee and ranged combat, and a unique casting system where the player draws runes in real time to effect the desired spell. The Arx Libertatis source code is based on the publicly released Arx Fatalis sources. This does however not include the game data, so you need to obtain a copy of the original Arx Fatalis or its demo.
Pioneer is a space adventure game set in the Milky Way galaxy at the turn of the 31st century. The game is open-ended, and you are free to explore the millions of star systems in the game. You can land on planets, slingshot past gas giants, and burn yourself to a crisp flying between binary star systems. Pioneer has a sneaking resemblance to Frontier: Elite 2.
ParaJVE is an advanced emulator for the GCE Vectrex game console (created in 1982 by General Consumer Electric). The emulation is mature enough to deliver a rendering close to the real machine, allowing you to enjoy most of the original games (as well as some extra homebrew ROMs). The emulator packaging is self-sufficient: it contains all the files needed to run the whole set of original vectrex games (including ROMs and hi-quality color overlays) and some additional homebrew games. It is perfectly legal for anybody to download, install and run this software, since the embedded ROMs are either public domain or homebrews whose authors gave written permission to include them in the ParaJVE package.
The Open Game Libraries is a collection of separately usable C++ libraries for creating games. It provides OpenGL window management, zip file management, OpenAL audio management, a developer console window, input management, bitmapped fonts with Unicode and kerning support, image loading and saving, model loading and importing, and generic classes and objects for game development such as math and text processing.