Diego Inácio has created several geometry tools for Houdini, using Python.
Houdini Demo Reel 2014
Side Effects Software has released the 2014 Demo Reel featuring the work of Houdini customers worldwide.
Houdini Engine for Autodesk Maya
SideFX have released Houdini Engine for Maya, with 3ds Max and Unreal versions coming soon.
Tea and Cookies in Houdini - Tutorial
Tea and Cookies in Houdini is a two part commercial tutorial in Houdini, going through all the steps of the scene's creation.