EDIT: I just realized after I wrote this that Sharepoint has some of this functionality (versioning) but imo is a bear to use.
My group (R&D) has been using a home-grown requirements management system for a few small projects, and ideally we'd move to that for our specs.
My group (R&D) has been using a home-grown requirements management system for a few small projects, and ideally we'd move to that for our specs.