If you are researching forum software you should include FUD Forum
. The two features that brought FUD Forum to my attention are:
- NNTP & Mailing List integration, allowing FUDforum to be used to archive newsgroups & mailing lists, as well as allow forum members to post messages to newsgroups and mailing lists via the forum.
- Threaded View (by default standard flat view is used)
There is a list of features
I played with it for a few months and thought it worked very well.