Collaboration software

Greetings everyone, Currently, our small staff of php, mysql programmers are all working from remote locations, and we would like to start implementing collaborative software. From reading an article in the Inc. Magazine they mentioned three general pieces of collaborative software ??" Groove, Microsoft SharePoint, and Socialtext Workspace. These programs above appear to be great, but we would like to embrace open source collaborative software, so the question is: Is there any open source collaborative software currently available? If there is which one do you believe is the best? From what I have read briefly SocialText Workspace began as open source, but SocialText is charging money being a distributor. We would like to find software that when new programmers join the force we won’t have to buy a licenses. Thank you greatly, Wade Willett P.S. Even if it only takes a few minutes to reply, please incorporate a bid amount. This way I can pay you for your efforts, and close the bid after. ## Deliverables 1)Just a answer ## Platform email, RAC reply