tailor

With its ability to "translate the history" from one VCS kind to another, this tool makes it easier to keep the upstream changes merged in a own branch of a product.

Tailor is able to fetch the history from Arch, Bazaar, CVS, Darcs, Monotone, Perforce or Subversion and rewrite it over Aegis, Bazaar, CVS, Darcs, Git, Mercurial, Monotone and Subversion.