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