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.
OTOY expands OctaneRender integration to NUKE, Houdini, Unreal Engine 4, and more
OTOY expands OctaneRender integration to NUKE, Houdini, MotionBuilder, Unreal Engine 4, and Digital Molecular Matter Engine.
SideFX have announced Houdini Engine, an API that will facilitate Houdini integration into proprietary studio software.