To build this module you need the GMP library installed on your computer. See: http://gmplib.org/ You will also need either Math::GMPz or Math::GMP Build in the usual way: perl Makefile.PL make make test make install If the GMP library is not in a location where your compiler finds it by default, then instead of running 'perl Makefile.PL', you'll need to run: perl Makefile.pl INC="-I/path/to/gmp_include" LIBS="-L/path/to/gmp_lib -lgmp" Any problems, I am contactable by email at sisyphus at(@) cpan dot (.) org. ========== MS WINDOWS ========== If building with an MSVC++ compiler against a MinGW-built gmp lib, you'll need to additionally link to MinGW's libgcc.a and libcoldname.a. First, create copies of the 3 '.a' files (named libgmp.lib, libgcc.lib, and libcoldname.lib) and then run: perl Makefile.pl INC="-IC:/path/to/gmp_include" LIBS="-LC:/path/to/gcc_lib -lgcc -LC:/path/to/coldname_lib -lcoldname -LC:/path/to/gmp_lib -lgmp"