BRL-CAD is a powerful cross-platform constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing for rendering & geometric analyses, network distributed framebuffer support, image & signal-processing tools.
Loki Render allows you to create your own render farm, serving Blender render jobs to a group of computers. Loki is easy to setup and runs on Linux, Windows or Mac, making it a quick and flexible distributed network rendering solution!