CPAN is stuffed with great, good, bad, and terrible code all mixed up together; there’s no consistent standards for versioning, there’s no consistent standards for coding; like Perl, there’s little, if any, consistent standards.
And that’s why it thrives. If it tried to enforce any of these to any extent, it would wither, like the repositories of other languages have.
PEAR, at the very least, is a wasteland. Ruby’s Gems thingie is doing better… but is orders of magnitude smaller than the CPAN. I don’t think Python has anything resembling any of these. Java’s central repository is called “Google” and the quality of stuff is all over the place – certainly less consistent than CPAN with its lack of standards… although the high-quality Java libs are consistenly good and well documented (though that barely makes the language any less unfun…). We’ll see where the JSAN goes – being a bit of an outlier in this set as it is.
Certainly I’ll take the CPAN over any of those.
Makeshifts last the longest.