ANSA is described as 'advanced multidisciplinary CAE pre-processing tool that provides all the necessary functionality for full-model build up, from CAD data to ready-to-run solver input file, in a single integrated environment'. There are more than 10 alternatives to ANSA for a variety of platforms, including Windows, Linux, Mac, Android and Windows Phone. The best alternative is Blender, which is both free and Open Source. Other great apps like ANSA are SALOME (Free, Open Source), Gmsh (Free, Open Source), MagicaCSG (Free) and PhotoAnim (Free).
HyperMesh is a market-leading, multi-disciplinary finite element pre-processor which manages the generation of the largest, most complex models, starting with the import of a CAD geometry to exporting ready-to-run solver file.
TetGen is a program to generate tetrahedral meshes of any 3D polyhedral domains. TetGen generates exact constrained Delaunay tetrahedralizations, boundary conforming Delaunay meshes, and Voronoi partitions.
enGrid is an open-source mesh generation software with CFD applications in mind. enGrid uses an in-house development for surface meshing and prismatic boundary layers; a module for hex far-fields will be added in the next release.