Lugaru source code was released under GPL license on 2010-05-11. This presumably only includes the game engine code and not the artistic assets. For more info, see: blog.wolfire.com/2010/05/Lugaru-goes-open-source
Lugaru HD is the same game but includes a fan-made high definition texture pack by Tim Soret which was originally available as a free mod to the game, but was at some point later (2009-05) included in the base game's download as well.
About Lugaru: The Rabbit's Foot
2010-05-11 (updated 2011-01-08) #