This is Perl module XS::MRO::Compat.
INSTALLATION
XS::MRO::Compat installation is straightforward. If your CPAN shell is set up,
you should just be able to do
    $ cpan XS::MRO::Compat
Download it, unpack it, then build it as per the usual:
    $ perl Makefile.PL
    $ make && make test
Then install it:
    $ make install
DOCUMENTATION
XS::MRO::Compat documentation is available as in POD. So you can do:
    $ perldoc XS::MRO::Compat
to read the documentation online with your favorite pager.
Goro Fuji (gfx)