I need to create and online community (for health-workers) as a school project and am currently hunting around for software solutions for this - preferably open source. The requirements include the usual features such as forums, user management, news, searching, links to health resource etc as well as blogs and perhaps and instant chat component. I have had a look at some Content Management Systems which provide many of these features either directly or via extension modules. I have also been researching individual sotware packages for forums, instant chat, blogs etc with the view to integrating them into a site built from scratch.
I would be extremely grateful for recommendation on open source solution for this undertaking and advice/suggestions on the route I should take (ie the prebuild and extensible CMS's or combining individual components)?
Incidentally the forum package for this site is looks quite impressive, is it open source :-)?