>Well it might be text files, word files, ACAD files etc... Is sourcesafe part of VFP?
>

No, it's a commercial source code management tool that is included in Visual Studio Enterprise, and can be added to VFP for less than the cost of VS Enterprise if you don't have VS.

Another product that can work as a source code control application for VFP is PVCS; it's no cheaper to add than VSS.