Gmsh - Gmsh is a 3D finite element grid generator with a build-in CAD engine and post-processor.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Altair - Visually Analyze Any Data at the Speed of Business
Quixel Mixer - Mixer is a PBR creation suite that uses brushes and non-destructive layering to generate all types of maps.
3D-Coat - 3D-Coat is the one application that has all the tools you need to take your 3D idea from a block of digital clay all the way to a production ready, fully textured organic or hard surface model.
NETGEN - NETGEN is an automatic 3d tetrahedral mesh generator.