GEM (Graphics Environment for Multimedia) is a library to be used with Miller Puckette's Max-like realtime-computermusic-software "Pure Data" (Pd), which allows to draw and control openGL- and pixel-graphics (like video) in realtime from within Pd.
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.