Software for electromagnetic simulation
Cross-platform Open-source 2D CAD
A canvas library for generating technical drawings
OpenNum lets you distribute solvers with a nice graphical interface
Free multiphysics simulation software package
An Open source Analysis and SImulation Toolbox for Fuel Cells
A package for Isogeometric Analysis in Octave and Matlab
Cuts 3D objects from polystyrene foam (EPS/XPS)