Coin is an implementation of Open Inventor. Open Inventor is the de facto standard API for retained-mode 3D graphics programming. Open Inventor has a highly extensible design, and has been designed to allow for rapid development of highly interactive 3D graphics applications in the fields of CAD, engineering, scientific computing, simulation, VRML, and visualization.
Moonlight|3D is a modeling and animation tool for three-dimensional art. It currently supports mesh-based modeling. It's a redesign of Moonlight Atelier, formed after Moonlight Atelier/Creator died in 1999/2000. Rendering is done through pluggable backends. It currently supports Sunflow, with support for RenderMan and others in planning.
OGRE (Object-Oriented Graphics Rendering Engine) is a class library written in C++ designed to make it easier and more intuitive for developers to produce games and demos utilising 3D hardware. It exposes a number of useful objects allowing you to create and manipulate a 3D environment and render it to your specifications, while removing the unnecessary complexities of the underlying system libraries like Direct3D and OpenGL.
libQGLViewer is a C++ library based on Qt that eases the creation of OpenGL 3D viewers. It provides some of the typical 3D viewer functionality, such as the ability to move the camera using the mouse, which is lacking in most of the other APIs. Other features include mouse manipulated frames, interpolated keyFrames, object selection, stereo display, screenshot saving, and much more. It can be used by OpenGL beginners as well as to create complex applications, being fully customizable and easy to extend. It ships with many examples and comprehensive documentation.
The Structural Proteomics Application Development Environment (SPADE) provides a community suite for developing and sharing protein structure and sequence tools. It includes a custom molecular viewer, sequence alignment editor, many reusable tools, and a chemical probing suite to support experimental verification of predicted structural models.