Diego Inácio has created several geometry tools for Houdini, using Python.
Houdini 15 Sneak Peek
Side Effects will be showing Houdini 15 at SIGGRAPH 2015, but first here is a feature trailer.
Arnold for Houdini
Solid Angle have released the first public release of their Arnold renderer for Houdini.
Houdini Engine for Autodesk Maya
SideFX have released Houdini Engine for Maya, with 3ds Max and Unreal versions coming soon.