I have a site where users maintain favorite lists. I want to add a discussion to each favorite list. A new discussion should automatically be created when a new favorite list is created and it should be displayed right below that list. I prefer to have a tree and to have the newest subject on top.
In some respects this looks like a CMS. However, I want each favorite list owner to administrate his own discussion.
Should I use forum or CMS software for this - and which package?
Well, good question. I think you'll have to use your own skills to write the favorite lists management in your website, and aside that, you can use any forum software with a well-designed API to automatically create the topic related to each favorite lists.
Of course, you can also do that with a CMS, and in this case, the "topic" would actually be the comments available for this specific node (in Drupal) / article (Wordpress / Dotclear).
About forum with well designed API, I think you can rely on Simple Machines and PunBB.
One of the most important thing is to remember that you'll have to centralize the management of your user accounts as well, else, the rights and roles are going to be really hard to manage and support.
FSR Admin - Vote for 2012.