I had heard the name 37signals before as they are a leading Ruby on Rails development house but I had never really thought of checking out what they were up to until this week. It turns out their Basecamp product is a very tidy project management tool with a rather large following. Feature-wise it is fairly simple and is completely centralised around the 37signals server farm (no local Intranet version). Rather than focus on email processes 37signals picks up on the blog model of posts and comments with a central (unversioned?) file repository. It appears their target audience is distributed Web developers who need a simple way to manage the comings and goings of a small group of workers.
Basecamp from 37signals (click to enlarge)