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.
HPGL-Distiller filters out aspects of an HPGL file which are not relevant for various HPGL output devices, typically vinyl cutters. Irrelevant codes are filtered out to prevent many vinyl cutters from responding poorly to the excess data. With the use of HPGL-Distiller, you can use Inkscape, QCAD, GIMP, and many others to produce appropriate vinyl cutting output results.
Versatile Encoder allows you to encode your own videos into good quality DivX files. The input can be a sequence of files (as generated by blender), a single file (if you want to recompress something), or a VCD (if you need to back up a movie). This piece of software tries to guess good defaults and to help the user in making choices.