[perigrin]

Not entirely true. Languages with strong static type systems like Haskell and OCaml go a long way towards being provably correct without test suites. Dynamic languages like Perl however have no such guarantees.

The fact that the cross product of several generations of interpreter, several platforms, and tens of thousands of distributions is generated automatically by a handful of volunteers is a strong argument for CPAN/Perl being unique amongst the dynamic languages in it's testing and compatibility.

Additionally, people who aren't in the right circles probably never know how much grepping through CPAN happens when new features and syntax is suggested for the core Perl5 language. All done by the porters to be sure that new syntax won't break existing code without some fore-knowledge. This is on top of the automated testing.