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.
QuartzCrystal is an application for rendering Quartz compositions to QuickTime movies and image sequences. It supports third party plugins (using both the official and unofficial API), as well as unsafe patches. It also supports spatial supersampling (antialiasing) and temporal supersampling (motion blur).
Mathnetics is an API for creating advanced, interactive, Web-based mathematical applications. It defines various important mathematical objects that are inter-related and on which many numerical calculations can be done. It also features rendering of 3D objects onto an SVG canvas (to do so, it includes certain utilities such as browser sniffing, DOM node selection, and DOM readiness detection), which is quite robust. A few basic 3D objects are given (Line, Sphere, Cube), but the user can define any 3D object desired as per the specification.