From the release of version 3.2, the py-stl software has been renamed to stltools. The reason I made this change mostly has to do with how FreeBSD handles packages. Programs that require an interpreter are prefixed with its name and version. So py-stl would become py27-py-stl, which would be silly.
This release also introduces a new backend module stltools. This module uses numpy arrays to contain the 3D coordinates. This should make manipulating large STL files faster.