I was using This is perl6 version 2014.09 built on parrot 6.7.0 revision 0 I'm now using This is perl6 version 2015.01 built on MoarVM version 2015.01 Perl 6 probably isn't as fast as Perl 5 on this task (sorry, haven't written an equivalent Perl 5 program) but in the past four months the Perl 6 I use runs 3.7 times faster. -mark