Open Source Solid Modeling CAD
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.
Ayam is a free 3D modelling environment for the RenderMan interface.
Lamia or Lamia Engine is the modern generation free distributable and open source game engine for creating computer games for several prevailing software platforms and very maybe hardware platforms either.
TkFax is a Tcl/Tk based GUI fax program supporting efax or sendfax. Its GUI is integration of make/send/receive faxes includs editing cover pages, attaching files, and optionally scanning documents by TkScan. All with multi language support.