Collaboration Web Based App

Hi all,

This may not be the correct forum for this; however, it concerns a website so here it is.

I'm working on a software development project. Does anyone have any suggestions for collaboration software, and open source is of course fine. We are looking for the ability to "check in and check out" code as well as whiteboarding and communications.

Something with features such as this:

http://cvw.sourceforge.net/cvw/info/docs40/jcvwscreen.php3

Thanks for any links or help. I've look at Sharepoint but wouldn't mind something that is ASP based and we could use Netmeeting for whiteboarding.