I recently attended a seminar that presented a brief overview on an collaboration software called Sharepoint. Its a MS product so it integrates with other MS products. It provides document sharing and tracking, ability to share links via calendars, it can utilize active directory to set file permission per user. It is advertised as a document management system. It keeps document history of revisions, it can be configured to notify users when a change has been made to a document as well as metadata being included with each document. Here's a link to some information, http://www.microsoft.com/technet/windowsserver/sharepoint/techinfo/topten.mspx
Here's a word document with a list of the services, http://download.microsoft.com/download/2/f/2/2f292511-8865-43ce-a241-5a4cc6dbfd03/WSSVersions.doc
There is also a Sharepoint Portal App and here's that info, http://www.microsoft.com/office/sharepoint/prodinfo/overview.mspx. There are some additional add-ons that may be useful, including a form tool that is supposed to be user friendly and can export data is database format, a report builder, SQL reporting services that will gather data from different databases and servers, Scorecard manager which allows a quick overview of a document, or projects progress, ability to autopublish reports or email status or update notifications.
Phil