TortoiseCVS lets you work with files under CVS version control directly from Windows Explorer. It's freely available under the GPL.
With TortoiseCVS you can directly check out modules, update, commit and see differences by right clicking on files and folders within Explorer. You can see the state of a file with overlays on top of the normal icons within Explorer. It even works from within the file open dialog. http://www.tortoisecvs.org/index.shtml
QVCS is a version control system that offers most of the features of other more widely known applications at a fraction of the cost. Compare QVCS to commercial packages costing more than 10 times as much. You'll find that QVCS offers a tremendous value. http://www.qumasoft.com/
Can these programs be used for storing changes to a hardware design, i.e. schematics, PCB, firmware, etc? How would one interface this to a PCB design program?
The question was "Can these programs be used for storing changes to a hardware design, i.e. schematics, PCB, firmware, etc? How would one interface this to a PCB design program?"
I am started to work with CVS , and its doc says that when adding files to code repository you can specify flag -kb means file is binary .