I'm considering starting an open-source project, so I shopped around some popular project hosting sites.
What I find surprising is that many (see here for a nice feature table) of the popular project hosting sites (e.g. GitHub, BitBucket) don't have a forum feature, i.e. a place where users can talk to the devs, ask questions, raise ideas, etc.
IMHO an active forum is an important factor in creating a user community around a project, so I would expect that most project owners would be interested in such a feature.
I've also noticed that some projects do have support forums (or mailing lists) hosted elsewhere - e.g. Ruby on Rails is hosted on GitHub but has a Google Groups support group, and TortoiseHG is hosted on BitBucket but has a mailing list on SourceForge - so it's not like this feature is unneeded.
So how come many project hosting sites don't have a forum feature?