It’s interesting to watch these programming tools – ahh, pun (originally) not intended – “go fork themselves.”   Python-3 is noticeably incompatible with its predecessors, even though it is an incremental improvement, because in order to make those improvements they tinkered with some of the cornerstones of the language.   PHP has also gone through a fair number of language incompatibilities.   Each time this happens, the language-camp divides in two, and both must find a way to continue to exist in parallel – not always easy.

And Perl?   Well, Perl did, too ... except for the fact that it “died trying.”   Perl-6, like it or not, never made it off the ground as “the grand successor to Perl-5 and the fixer of all things (someone) thought to be wrong with it.”   So, Perl never [successfully] forked itself, and this might actually turn out to have been a very good thing for Perl.

Perl remained Perl-5, and it started inheriting some remarkable things, like Moose, which were actually built in and using the Perl-5 language system.   No other language that I know of ever did that.   None can say, no Moose;.   The amount of installed software in CPAN continues to grow, even as it remains compatible with what has been out there for so many years now.   Although Perl tried to fork itself, it never did, and I think that it ... yes, warts and all ... continues to grow more valuable as a result.

But no, not “at the expense of” or “versus” any of the others.   Programming tools live alongside one another, like it or not, and we wind up using them all, like it or not.   (Perl: “like it.”   Everything Else: “not.”)