RawTherapee is a powerful, cross-platform raw photo processing program, released under the GNU General Public License Version 3. It is written in C++ using a GTK+ front-end and a patched version of dcraw for reading raw files. It is notable for the advanced control it gives the user over the demosaicing and developing process.
Website: http://rawtherapee.com/
Official documentation: http://rawpedia.rawtherapee.com/
Download RawTherapee: http://rawtherapee.com/downloads
Download source code tarballs: http://rawtherapee.com/shared/source/
Source code documentation: http://michaelezra.com/projects/rt/documentation/
Git handbook: http://git-scm.com/book/en/
Compilation, branches and Git
Refer to RawPedia for a detailed explanation of how to get the necessary dependencies and how to compile RawTherapee.
Linux: http://rawpedia.rawtherapee.com/Linux