Diego Inácio has created several geometry tools for Houdini, using Python.
Nyx Sidekick - Preview
Here's a sneak preview of Sidekick, through which 3ds Max can communicate directly with Houdini.
Digital Tutors - Introduction to Houdini 15
Digital Tutors have released a tutorial introducing you to Houdini 15.
Houdini 15 Sneak Peek
Side Effects will be showing Houdini 15 at SIGGRAPH 2015, but first here is a feature trailer.