There is no "Perl6".
One day I typed "brew install perl6" on my computer and now I can enter things like "perl6 -e 'say X'" and wonder what it means. I also have several versions of Perl 5 installed! I don't have Perl 1-4 but do wish perlbrew would add the best stable version of each, so we can have ever more fun. I want more Perl, not less, more!
I recently installed "gnuradio" which resulted in 2 additional versions of "Python" 2 and 3 being "unbottled" by "homebrew" on to my computing device. This is in addition to the many more versions of "Python" automatically installed by applications on my computer, including at least one that facilitates my otherwise wonderful Perl IDE (Komodo :( Free :)
I guess the paradigm involves multiple versions of Perl running simultaneously to handle each computationally heavy aspect of a modern application like, for an IDE: 1. the GUI and 2. syntax highlighting and 3. real time eval and 4. perl critic and etc. No big deal on modern systems cause Perl is so tiny...