Diego Inácio has created several geometry tools for Houdini, using Python.
Side Effects Software have announced the release of Houdini Indie for independent animators and game makers.
Houdini 13 Update
Side Effects's latest version of Houdini 13 comes with new particles, finite element solver, lighting workflow and more.
Houdini - Demo Reel 2011
Check out this demo reel showcasing some of the best work achieved with Side Effects Software's Houdini.