Is there an open source alternative to Windows Volume Shadow Copy

Question

Is there an open source alternative to Windows Volume Shadow Copy?
I need to keep previous versions of files in a directory
automatically without having to use a check in / check out
process or a traditional version control system.
Additionally, the platform I need this on is Windows XP and I've found that the
Windows Volume Shadow Copy is only available on the Server Windows versions.

Answer 1

I found a Wikipedia entry here and was able to find a Windows XP application here