I have been using the RCS http://www.cs.purdue.edu/homes/trinkle/RCS/ at the command prompt. Have to be careful with VFP binary files though (.SC? etc)

Also, you might check http://www.componentsoftware.com/ it is suppose to be somewhat MS complient.

HTH,
Cris

>Has anyone used CVS or SourceGear Vault? I'm interested to hear what alternatives you've used to VSS (especially inexpensive ones)
>
>Mike