In my organization we have successfully implemented SVN using a Windows server running Apache and for client access we use TortoiseSVN. The server is configured to access our information via LDAP.
We not only use it for keeping track of HTML code that goes into a huge content management system, but we also use it to store supporting documents and wireframes for those pages that are in Microsoft Word document form. TortoiseSVN diff is amazing for our Word wireframes. It will use change tracking built into Word to show us the customer changes made to the wireframes.
The drawback is that TortoiseSVN did have a learning curve and we actually had to teach users how to use it and the users were already technically savvy. So it will be really difficult to get average users to use TortoiseSVN properly.