LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
Cura - Cura aims to be a end solution for personal 3D printing with RepRap based machines.
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.
FreeCAD - An open-source parametric 3D modeler
Slic3r - STL-to-GCODE translator for RepRap printers Here comes Slic3r! Its features are: - speed
OpenSCAD - OpenSCAD is a software for creating solid 3D CAD objects.