Slic3r - STL-to-GCODE translator for RepRap printers Here comes Slic3r! Its features are: - speed
Autodesk DWG TrueView - Get a free DWG viewer to view, open, edit, and convert .dwg files, the native file format for AutoCAD files. DWG Trueview includes DWG TrueConvert.
Repetier - Software for controlling RepRap style 3D-printer like Mendel, Darwin or Prusa mendel.
Autodesk Design Review - Design Review lets you view, mark up, print, and track changes to 2D and 3D files.
MatterControl - MatterControl is a free, open source app that lets you organize and manage your 3D prints.
ZWCAD Viewer - Cross-Platform .DWG | .DXF | .DWT R12-2013 Viewer