The Indie Game Jam is a yearly experimental game design event. Professional game developers create a custom game engine and make games with it over four days. The results are shown at the GDC & indiegamejam.com, and the code is GPLed on sourceforge.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.