Yes, here it is at last the Engine that made the Penumbra Series.
Read through the TODO file for various known things that should be cleaned up / fixed.
Included are project files for Xcode, Visual Studio 2003 and Cmake (for Linux)
We encourage everyone to contribute code to this project, so just sign up for a github account, create a fork and hack away at the codebase. We will start an Open Source forum on the Frictional Games forums as a place to talk about changes and to submit patches from your forks.
All code is under the GPL Version 3 license except for the "test" which are included under the ZLIB license. All of the assets are licensed under the Creative Commons Attribution Share-Alike 3.0 license except for the CG shaders which are under the ZLIB license. Please read the COPYING and LICENSE-* files for more information on terms of use.