FreeCAD

FreeCAD is a great 3D parametric CAD project. Many specific modules are being developed, including road alignment and finite element structural analysis. However, the most common use is 3D modelling. It also includes import and export of IFC files, so it could be suitable for BIM projects. I have not yet gone deep into FreeCAD.

AirFreeCAD

A small macro to open airfoil files, either in standard .dat format or the specific .txt format used by Laboratori d'envol.