I've spend the last 2 weeks of my life fighting with CommunityServer, and as far as I can determine, this is a product that is NOT designed for other developers.
Lack of documentation. Lack of up-to-date examples or explanation of the layout of the SDK means that a typical developer spends weeks and weeks in the dark about where things are.
Forums are completely useless - with questions and answers relating to older versions that doesn't apply.
If you are after a good Blog/Forum/CMS software, look elsewhere.