Cura - Cura aims to be a end solution for personal 3D printing with RepRap based machines.
FreeCAD - An open-source parametric 3D modeler
Slic3r - STL-to-GCODE translator for RepRap printers Here comes Slic3r! Its features are: - speed
MacDraft - MacDraft Professional, powerful 2D CAD, drafting, technical illustration, architectural drawing and...
Repetier - Software for controlling RepRap style 3D-printer like Mendel, Darwin or Prusa mendel.
ImplicitCAD - ImplicitCAD is a programmatic CAD program, implemented in Haskell.