It would be nice to have a forum creating software become available.

With free forum software like PHPBB and SMF Forum that have an easy installation script, ready made free templates, easy administration, and numerous help sites out there, along with paid forums, I can't really see a CC market for this.

Forums can get quite large in size, hence the mysql database to support it. I don't know if an xml file or text file will support a large forum.

My personal favorite free forum script is phpBB, but you'll need to have mySQL on your server to run it, and if you're not familiar with the database structure of your server, you'll want to have a MySQL administration console... it makes it a lot easier to manage your databases (free as well, but your webhost may charge for that service).
If you haven't got much time, and want to see what the new phpbb3 can offer, just try it out on this host : free forums

Hope this can help!