What belongs in a Content Managment System?

Im planning to build a small content management system for my medium sized site. I have a brief idea of what i want in it, but what makes a good CMS? What things would you like to have it?
Should it be web based or in some other form? What do big name CMS systems have in their app?

full text search of body text, titles, and attached documents is key. Relevancy ranking is too.

Good organization structure (multi-level document categories), multiple access levels for viewing and editing

Good normalization of data- which will allow for easy mass-changing of documents.

Store files on the filesystem, not in a DB. All HTML should be templatted, and not mixed in with code.

Newsfeeds brought in (and exported) via RSS/RDF.

javascript/ client-side scripting used minimally (many systems I've seen use it so much that you can't do any management unless you're in IE. LAME.).

Object caching for document view- e.g. not everything dynamic you look at generates a DB query. Major time saver.

I've built a system that does all of the above (and a lot more) using mod_perl, CGI::Application, HTML::Template, DBIx::FullTextSearch and MySQL. Though my system rocks, if I had it to do again I'd probably start with OpenInteract or Apache::AxKit.

I suggest you check out OpenInteract, Apache::AxKit, Bricolage or Zope as very, very good places to start out.

Everyone I know that uses Zope, after they get past the intial learning curve, loves it.

killerasp,

Creating and editing content should be the basis of any content management tool you create. This also includes attaching/uploading files that will need to be shared by multiple groups. Once you've addressed this basic functionality, you can move onto input result queues, user permissions, and other more advanced features.

Scully Interactive (URL) has a cost effective custom content management system that is a nice approach because it is built specifically for each Web site is serves. You may want to take a look at their CM demonstration and some of the sites from their portfolio as examples of how this comes together.