Diego Inácio has created several geometry tools for Houdini, using Python.
Digital Tutors - Introduction to Houdini 15
Digital Tutors have released a tutorial introducing you to Houdini 15.
Houdini 14 - Sand/Snow RnD
Graham Collier has created some sweet sand and snow tests using the new Houdini 14.
Side Effects Software have announced the release of Houdini Indie for independent animators and game makers.