FreeCAD - An open-source parametric 3D modeler
DataCAD - DataCAD is a computer-aided design and drafting software for 2D and 3D architectural design and drafting
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
AutoCAD Arch - Design and document more efficiently with the AutoCAD Architecture toolset, created specifically for architects.
Onshape - Onshape is the first full-cloud 3D CAD system. It runs in a web browser and on any mobile device.
AutoCAD Plant 3D - AutoCAD Plant 3D is a BIM software that lets you create, modify, and manage schematic piping and instrumentation diagrams.