Free and open source pattern design software
Software for electromagnetic simulation
Open Source Planar Linkage Mechanism Simulation and Synthesis Software
OpenNum lets you distribute solvers with a nice graphical interface
Open Knowledge on engineering development.
This plugin exports G-Code for a wirecutter
An Open source Analysis and SImulation Toolbox for Fuel Cells
CNC control software
Open Source FabLab Project
dedalo is a 2d cad drawing software written in python3.