a parametric 3D CAD modeler
Free and open source pattern design software
LibrePLM integrates CAD editors in Odoo / LibrERP
Open-Source Multiphysics FEA (FEM) Package
cppcam is a 3D CAD app for drafting G-Code toolpaths for CNC Routers
Free multiphysics simulation software package
2.5D CAD CAM emphasis on CAM and toolpaths
CNC machine code generation for 3D models
ALST is a CAD for all imaginable logic systems (binary, ternary, etc)
Cuts 3D objects from polystyrene foam (EPS/XPS)