Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Goxel - Goxel is a simple, but powerful voxel graphic editor with 24-bit color support, unlimited scene...
MagicaVoxel - A free lightweight GPU-based voxel art editor and interactive path tracing renderer.
ZBrush - ZBrush is a digital sculpting and painting software solution.
Paint 3D - Paint 3D is a standalone graphic editing solution created by Microsoft.
Sculptris - Sculptris: Enter a world of digital art without barriers.