If you are looking for a source control solution...
You should definately check out and read up on Subversion (SVN), TortoiseSVN and Ankh. Subversion is the version control system. It can run under a windows service, file system type repository or under Apache.
We have it running with Apache on a port other than 80. TortoiseSVN is for windows shell integration. Ankh is for Visual Studio IDE integration. There are articles out there that talk about how to use SVN with SQL server.
SVN uses a different process than VSS. It doesn't really do locking. It's more of an optimistic merging/updating process when needed. The documentation covers in depth how the tool/process works http://svnbook.red-bean.com/
We are successfully, using these products at work. They are far superior to VSS. At home, I use Ankh and TortoiseSVN with an external USB drive for the file repository.