There's a lot of Git-interface modules on MetaCPAN.

• Git::Repository — Has an impressive number of reverse dependencies. Bills itself as a "low-level interface" to Git.
  • Implicitly requires Perl v5.12.0, because Pod::Eventual is in its dependency tree and Pod::Eventual explicitely requires Perl v5.12.0.
  • As far as I know, it is impossible to skip a dependency when installing a CPAN module... even modules that seem minimally-related at best.
• Git::Raw — An interface to libgit2. Surprisingly complete. There's quite a bit of code here!
• Git::Database — An interface to quite a few other Git-oriented Perl modules.
• Git::Background — Very new, but interesting. Uses futures.
• (older) Git — A low-level interface to Git.
• (very old) Git::Sub
• (very old) Git::PurePerl
• (very old) Cogit