VoroFrag is a free modifier that allows to make voronoi fragmentation. It handles convex and concave objects, as well as hollow meshes and open surfaces. It offers a "Box Mode" for quick fragmentation. Support for mapping coordinates, material ID and normals.
!! Update 2.5 !!
You will find the full documentation (in pdf), the change_log and the plugin in the attached file (VoroFrag_v2.5.zip)