DotNetNuke is a Web Application Framework ideal for creating and deploying projects such as commercial web sites, corporate intranets and extranets, online publishing portals, and custom vertical applications. For more information go to the official web site.

This web site also is powered by DotNetNuke release 4. I have a big experience in developing modules and skins for this framework.

In the Articles & Tutorials section you can find some information for implementing new features and optimizations.