Blender - Blender is the open source, cross platform suite of tools for 3D creation.
AutoCAD MEP - AutoCAD MEP software helps you draft, design, and document building systems.
MakeHuman - MakeHuman is a free, open source, interactive modeling tool for creating custom 3D human characters.
DataCAD - DataCAD is a computer-aided design and drafting software for 2D and 3D architectural design and drafting
Bforartists - Bforartists is a fork of Blender.
iConstruct - iConstruct is a business information modeling (BIM) software for Autodesk Navisworks, suitable for a large range of industries worldwide.