The most active Houdini community on the web, odForce provides a great tools such as the odwiki and odForums that bring together top professionals and new users from around the world. If you want to learn Houdini then you will want to be a member of this site.
CG Talk | CG Society
Join Houdini users on this popular CG site then post examples of your work or enter contests to help drive your skills with the help of your colleagues. Also a great source for CG news.
Houdini Toolbox is a site dedicated to providing free to use tools and
educational materials specializing in tool development with Houdini.
A site dedicated to building and sharing Houdini tools and scripts.
HoudiniStuff is a community oriented resource providing tools used to exchange files between Houdini and other 3D/VFX packages.
3Daet.com is a project-based Houdini knowledge repository whose mission originated from a desire to establish a resource for visual effects students learning Houdini at Santa Monica's Academy of Entertainment Technology.
3D Buzz has a great collection of Houdini tutorial videos covering a variety of topics. The new Houdini Fundamentals course is a great introduction to the latest version of Houdini. Forums are also available for support and lively discussion.
This site provides a community for Houdini users in Russia. A valuable resource for everyone interested in learning about the CG community in that country.
This site provides a community knowledge-base for Houdini and RenderMan users in Korea. A valuable resource for everyone interested in learning these products.
A vibrant Korean Houdini Community site maintained by Korean Houdini Artists. Join now and take part in a Houdini Quiz, VFX Challenges and read Artist Interviews.
TDT 3D is designed as a meeting place for both French and English CG artists. The site also includes news, galleries, contests and other CG-related material.
Visual Effects Society
The Visual Effects Society is an organization comprised of visual effects professionals who desire to honor, advance and promote visual effects for its membership and the industry as a whole.
XING Houdini Gruppe
A Houdini group on the XING network created for German 3D artists. Moderated by Christian Kelch and Martin Matzeder. - "Diese Gruppe dient dem Erfahrungsaustausch mit der high-end 3D software Houdini. "
The Houdini user's group of Toronto holds meetings where you can learn how Houdini is being used in production.
London User Group Blog
The Houdini user's group of London is now holding meetings every Thursday -everybody is welcome expert or total newbie!.
This user's group in Germany called procedurale holds meetings to discuss Houdini and its procedural approach.
This user's group in Montreal holds meetings to promote the use of Houdini.
Andy Boyd has worked in the VFX industry for 10 years. He is currently Head of 3D Commercials at Framestore-CFC. Visit his site for some useful tutorials and a great Houdini gallery.
Fabio D'amico is a 3D artist based in Italy and specializes in character modeling and rigging. Visit his site to see a gallery of his creations.
This site is a great place to find Houdini widgets and gadgets including HDK tools, VEX Operators, and HDA's.