B.FX - A few interface scripts, shaders, and links to Houdini site.
El Kabong - Discover the 10 basic tricks, plus 3 more that combine the tricks for the CHOPs Editor in Houdini.
Expression2houdini - Two tutorials one will show how to set up a simple control panel using expressions, the other faking global illumination in Houdini with Vmantra.
od[force] - Serving the Houdini community with scripts, shaders, tutorials, plugins and codes. A forum is available for help and links to other Houdini related material.
Side Effects Software - Creators of Prisms and Houdini, procedural 3D animation and special effects tools for film, broadcast, entertainment and visualization production.
Using Houdinis Particle System - A quick example of how to use particles to create a field of grass complete with a gentle wind blown effect in Houdini. The file has two components: the source geometry and the particle system.