I have been looking for collaboration server/client solution. Which will allow to comment my articles/pages and provide “XXX comments” with AJAX ability to preview and add user comment. The only problem, none is supporting complex suite, which will include treeview discussion UI, RSS feeds and newsgroup.
It was surprise that on collaboration view, there is NO threads as tree. Say, Thunderbird IMAP client allow to watch mail in “discussion mode”. So instead of plain message list I am able to see only root/starter messages. That is a way to go!

Meanwhile, I am still looking for solution. The Syrus IMAP server has an option to publish shared folder as netnews (NNTP) discussion groups. That gives server side. But I have not found threaded UI for IMAP and administration UI. Probably, it will be easier to create own Web2.0 widgets?

Proposals:
- make collabotarion as treeview,
configurable from admin:
- publish IMAP shared folders on NNTP
- save each message in separate file.
It will allow:
- AJAX to use HTTP for direct message access, list messages in folder, etc.
- easy archieving/migration
- version control (SVN)
- name other reasons...

The best,
suns