BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
PLIB is a set of libraries to write games and other realtime interactive applications that are 100% portable across a wide range of hardware and operating systems. It's used by Majik3D, FlightGear, and others, and includes libraries for GUI widgets, sound replay, geometry, scene graph, joystick, and fonts/text.
QGLViewer allows people programming in OpenGL to play around with three dimensional scenes or to write software that uses OpenGL. It provides a set of classes for camera control, as well as comfortable user interface that allows you to control your viewing parameters via mouse and buttons. A framework for camera paths and their interpolation is provided, as is a simple scene tree. QGLViewer is object oriented and programmed in C++ such that the programmer simply instantiates a viewer and connects it to their own render routines.
freeglut is intended to be a 100% plug-compatible clone, and is released under the Xfree license. The GLUT (OpenGL Utility Toolkit) is a widely used library for doing window control, keyboard, and mouse input, and other basic functions for OpenGL programs. However, GLUT is not OpenSourced - although it's source code is available under a somewhat ill-defined set of restrictions. Hence, 'freeglut'.
OpenSG is an Open Source scenegraph system. Its design goals include high performance, multithread-safe data handling, high flexibility, extensibility, and portability to Irix, Linux, and Windows. A number of computer graphics research institutions are actively working on moving the system beyond the state of the art to include features like clustering, subdivision surfaces, occlusion culling, and more.
white_dune is a graphical VRML97/X3DV editor, simple NURBS/Superformula 3D modeller, animation tool, and VRML97/X3DV commandline compiler in development. VRML97 (Virtual Reality Modeling Language) is the ISO standard for displaying 3D data over the Web via browser plugins ("HTML for realtime 3D"). X3DV is the direct successor of VRML97. VRML97 and X3DV have support for animation, real-time interaction, and multimedia (images, movies, and sounds). white_dune can read, create, and display VRML97/X3DV files and let the user change the scenegraph/fields. It also has support for stereoscopic view via "quadbuffer"-capable stereo visuals, and support for 3D input devices like a joystick, spaceball, or magnetic tracker.
OpenEXR is a high dynamic range (HDR) image file format developed by Industrial Light & Magic for use in computer imaging applications. It includes support for 16-bit floating-point pixels (compatible with NVIDIA's Cg shader language "half" datatype), several lossless compression algorithms, and extensible image metadata attributes.