NETGEN Alternatives
NETGEN is described as 'Automatic 3d tetrahedral mesh generator. It accepts input from constructive solid geometry (CSG) or boundary representation (BRep) from STL file format' and is an app. There are more than 10 alternatives to NETGEN for a variety of platforms, including Linux, Windows, Mac, BSD and Snapcraft apps. The best NETGEN alternative is Blender, which is both free and Open Source. Other great apps like NETGEN are Wings 3D, MagicaCSG, picoCAD and SALOME.

