As promised when the Humble Indie Bundle
hit $1 million in donations the other day, indie developer Frictional Games has
released Penumbra: Overture's source code. "The code for
Penumbra: Overture is a continuation of the one used for the tech demo + some addition for the not so long lived Robo Hatch project. It also contains some code from
Unbirth, giving it quite some history." The release also includes the HPL1 engine. "This is engine that has powered all of the
Penumbra games and it even includes the stuff used to create the 2D platformer
Energetic. The engine code was started in December 2004 and was actively developed until early 2008." The repositories are
available at github.