a parametric 3D CAD modeler
An EnergyPlus shell for parametric studies and more ...
Extensible Line-drawing & Polygon-filling Rasterization Libs for Java
Static and Dynamic Structural Analysis of 2D and 3D frames.
A canvas library for generating technical drawings
OpenNum lets you distribute solvers with a nice graphical interface
CAD 2D for Land Surveying and Civil
Cuts 3D objects from polystyrene foam (EPS/XPS)
Open Source CAD