Crystal Blue is a multiplatform game engine aiming to be small, simple, extendable, and scriptable. The scripting language is Python, the main language is C++.
Blender 3d, with a Python script to export data, is the main content creator.
glChess is an open source 2D/3D chess interface for the GTK+/Gnome desktop. It is designed to have a clean and simple interface. Games can be played between human players and compatible 3rd party artificial intelligences.