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)