Modules that provide OS-specific behaviors often need to know if the
current operating system matches a more generic type of operating
systems.  For example, 'Linux' is a type of 'Unix' operating system and
so is 'FreeBSD'.

This module provides a mapping between an operating system name as given
by $^O and a more generic type.

WWW: https://metacpan.org/release/Perl-OSType