I'm never sure why people try to make the comparison with communityserver, aside from being a web application written in .net, they're as different from DotNetNuke as chalk and cheese. I was never a fan of community server, as they bought up a number of excellent (and free) opensource .net projects such as .text, and immediately made them commerical. Over time they added more and more restrictions, until nowadays they essentially abandoned their free users. They were not and are not an opensource project , which they didn't claim (http://telligent.com/communities/technical/communityserver/community_server_2008/w/cs20085docs/is-community-server-open-source/revision/1.aspx), though the concept of "shared source" (an oxymornic name itself) confused many people.telligent have always been a commercial company.

DotNetNuke however, has always and will always be an opensource project. Nik describes the opencore model we use @ http://www.dotnetnuke.com/Community/Blogs/tabid/825/EntryId/2225/DotNetNuke-Business-Model-and-Product-Roadmap-Part-1-of-2.aspx and http://www.dotnetnuke.com/Community/Blogs/tabid/825/EntryId/2226/DotNetNuke-Business-Model-and-Product-Roadmap-Part-2-of-2.aspx . The key item to note is that there is a single code base i.e. when I make security fixes I make them in 1 place and as both CE and PE are based on this single codebase (opencore) they both benefit from them. There is no way to remove features from CE, without removing them from PE, due to this common core, so that is not a concern.

The reaility is that PE is simply a set of extensions (modules,skin, httpmodules etc) that use the same extension points as always., as well as services (application integrity checking etc.) and a support offering. Any 3rd party could actually replicate this by buying or building similar extensions and services, the hope is that people will understand that buying them from DNN Corp means that the money made can pay staff who work on the bugfixes/enhancements etc., many of which are made in the opencore and hence benefit all users.

Cathal