bill - 12:03 am on Oct 11, 2008 (gmt 0)

MovableType.

Make a separate blog for each group. Then give them rights to edit the pages for the individual section. Each blog can be set to publish to its own folder/subdomain. The styles can all be linked together so that you have a unified look, or each section can use its own individual style.

MT is well known for its blog software, but it works fine as a CMS. It's dead simple for end users to enter content with its WYSIWYG input editor.

If you opt for the paid version you get online and phone support options.