http://dev.perl.org/pm/pos.html mentions the following risk in perl6
development:
> 4.We produce a slower interpreter.
This is a very definite concern, and we need to come up with ways to
mitigate this risk quickly. As Fred Brooks says, "Performance
Simulator. Better have one. ... Start it very early. Listen to it
when it speaks." I propose that the QA group be charged with the
responsibility of seeing to it that Perl6 is not slower than Perl5.
They should take care of setting up some benchmark tests, and solicit
volunteers to run those benchmarks weekly/monthly/whatever during the
implementation phase.
It is very easy to create something that is unacceptably slow and
not realize until toward the end of the process.
J. David Blackstone