libmng -THE reference library for reading, displaying, writing and examining Multiple-Image Network Graphics. MNG is the animation extension to the popular PNG image-format.
JEuclid is a complete MathML rendering solution, consisting of: a MathViewer application, command line converters from MathML to other formats, an ant task for autmated conversion, display components for AWT and Swing and a component for Apache Cocoon
G3D is a commercial-grade C++ 3D engine. It is used in commercial games, research papers, military simulators, and university courses. G3D supports real-time rendering, off-line rendering like ray tracing, and general purpose computation on GPUs. As of January 16, 2018, SourceForge is again the home of the active repository for G3D.
This Minimal OpenGL Utility Library is a library similar to GLUT, only with fewer features! You can write window-system-independent OpenGL programs with even fewer lines of code than GLUT. Initial support for X11 and Win32. Examples.
OpenArena is a 3d game creation engine. It is a rendering system that can be used for more than just games but it is targeted at games. The basic use being create some game media textures models maps and config files for physics and rules.