require 'version_sorter'
versions = %w( 1.0.9 2.0 1.0.10 1.0.3 )
VersionSorter.rsort(versions) # => ["2.0", "1.0.10", "1.0.9", "1.0.3"]
VersionSorter.sort(versions)  # => ["1.0.3", "1.0.9", "1.0.10", "2.0"]

$ gem install version_sorter