Diego Inácio has created several geometry tools for Houdini, using Python.
Houdini for Games - Frima Studio
See how Frima Studio use Houdini to generate content for their games.
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.