Arx Libertatis logo
Arx Libertatis is the name of the GPLv3-ed Arx Fatalis (proprietary game) engine. It features a unique "draw symbols to cast spells" magic system and has an own scripting engine (described as "a mess, but at least a human readable mess").
The game engine runs the proprietary game with tolerable lag in some game areas on an ASUS EeePC 1000H netbook on Linux and I am close to completing the game from start to end. It can also be compiled on Windows and OS X. A stable release is not yet finished.
Can Arx Libertatis be used to create a free-as-in-freedom game?
No. Not yet.
As-is, i don't think creating custom models, etc. will be easy. We will add support for more common formats in the future, but for now our focus has been on porting and cleaning up the engine and there is still lots to clean up.
dscharrer of #arxfatalis
While image and sound files are in common formats, 3d models are in a format that mostly has not been explored.
If you're interested to dig deeper into the project's status, I recommend starting with reading the mission statement and filetypes wiki pages.