As you probably know by now, LรโVE is a framework for making 2D games in the Lua programming language. LรโVE is totally free, and can be used in anything from friendly open-source hobby projects, to evil, closed-source commercial ones. Read more about nlove (Love 2D) v0.6.2 (Beta) (Dingoo Linux misc)
Aleph One is a game engine currently in development by the Open Source community. It is based on the source code of Marathon 2: Durandal, a game created by Bungie Software in 1995. Since Bungie released the source code, Aleph One has matured to include a variety of new features and improvements. Read more about Aleph One v0.7 (Dingoo Linux misc)
ScummVM is a program which allows you to run certain classic graphical point-and-click adventure games, provided you already have their data files. The clever part about this: ScummVM just replaces the executables shipped with the games, allowing you to play them on systems for which they were never designed! Read more about ScummVM v1.2.0 (Dingoo Linux misc)