The current release of the Fabula Open Source Game Engine uses art from the Whispers of Avalon project released here at OGA.

Fabula is an Open Source Python Game Engine suitable for adventure, role-playing and strategy games. It offers a client-server architecture, an event-based protocol, multiplayer and networking capabilites, a multi-threaded server, an abstract, visualisation-agnostic model of a game world, an asset manager and a plugin system. Gameplay can be recorded and played back. The code is well documented and runs on Linux and MS Windows (it should work on OS X, too, but this has not yet been tested).

Fabula can be used as a library to develop your own games. As an alternative, you can use the Pygame-based graphical editor and the default game engine that come with fabula.

Website: http://florian-berger.de/en/software/fabula

Warning: Currently (v0.7.0, July 2011) Alpha all over the place. Proceed with caution.