Software

License

Experience Level

Website

Autodesk 123D

Freeware

Beginner

​http://www.123dapp.com/​

OpenSCAD

GNU GPL

Amateur

​http://www.openscad.org/​

FreeCAD

GNU LGPL

Amateur

​http://freecadweb.org/​

Seamless3D

MIT

Intermediate

​http://www.seamless3d.com/​

Google Sketchup

Freemium

Intermediate

​http://www.sketchup.com/​

SolidWorks

Commercial

Expert

​http://www.solidworks.com/​

Blender

GNU GPL

Expert

​https://www.blender.org/​

Rhino3D

Commercial

Expert

​https://www.rhino3d.com/​

Software

License

Capabilities

Website

Netfabb basic (free)

Freeware

Fill missing triangles, flip inverted triangles, and more

​http://www.netfabb.com​

Slic3r (free)

Freeware

Capable of splitting a STL assembly into multiple STLs, merge STLs together, and create build plates

​http://slic3r.org​

Materialise Magics

Commercial

A combination of Netfabb and Slic3r

​http://software.materialise.com/magics​

Autodesk Meshmixer

Freeware

Use it to import stl files and manipulate them. You can split parts, add joints, merge parts, and add shapes to parts (like cubes, spheres, weird features)

​http://www.meshmixer.com/​

Slash 3D

Freeware

Import STL models and hack away at them like Minecraft, or make blocked things from scratch and download as an STL.

​https://www.3dslash.net/index.php​