This is basically a open source library project aimed at developers. It's dual licensed and all version would need a registration on our site to run end product.
What would be best channels for offering support for developers? I'm thinking forums, mailing lists, etc.
Maybe even use a site like SourceForge, but then going on our site for registration key seems unnatural.
/JaanusSiim
Make the site simple and to the point.. Add forums, mailing lists, possible a wiki.
trac. Hands down.
Atlassian also has some pretty cool developer tools that you can get for free if your project is open source (but there's an application process involved).
The combination of open source and registration seems rather odd to me. The two don't normally go together.
That said, a simple, easy to navigate site is the way to go, possibly with a forum/wiki for your users.