http://www.perlmonks.org?node_id=879519


in reply to RFC: How to Release Modules on CPAN in 2011

Distribution version numbers
It may be noted that version numbers can be highly confusing. CPAN considers 7.100 and 7.1 to be the same version. The result is that it considers 7.10 to be an older version than 7.9. OTOH, 7.10.0 is newer than 7.9.0. CPAN orders the versions as:
7.10 < 7.9 == 7.9.0 < 7.10.0 == v7.10
So, 7.9 and 7.9.0 are consider the same version, but 7.10 isn't the same as 7.10.0!

My advice: when writing Perl software, avoid dots in version numbers. Otherwise, it will confuse people.