Moonlight 3D - A GPL modelling and animation tool. Screenshots, forum, documentation and download. - http://www.moonlight3d.eu/
Rayshade Homepage - Rayshade is rendering system for creating ray-traced images. - http://www-graphics.stanford.edu/~cek/rayshade/rayshade.html
MindsEye - Rendering and modelling package. - http://mindseye.luna.net/
GNU-realistic GMAN - GNU GMAN is an implementation of the RenderMan interface specification. It is a high-quality renderer supporting zbuffer, radiosity, distributed raytracing, spatial and temporal anti-aliasing (motion blur), surfaces such as NURBS and patches, and o - http://gman-toolkit.sourceforge.net/