Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Lychee Slicer - A POWERFUL AND VERSATILE SLICER FOR SLA RESIN 3D PRINTERS With Lychee, prepare your 3D models for 3D printing: define the best orientation, create supports automatically, or manually, preview before sending them to your 3D printer.
FreeCAD - An open-source parametric 3D modeler
Slic3r - STL-to-GCODE translator for RepRap printers Here comes Slic3r! Its features are: - speed
Sculptris - Sculptris: Enter a world of digital art without barriers.
Cura - Cura aims to be a end solution for personal 3D printing with RepRap based machines.