So here's my take on it:
1. Syntax. And how it's almost impossible to change it after a certain level of language-adoption. Perl coders knew it needed to be radically changed, understood how that was impossible, and moved on.
2. As a result of 1: the shrinking community. It is a clear red flag, no-one wants to start a project in based on (soon to be) legacy technology.
3. The existence of very suitable languages for Perl-refugees. When Perl ruled the web it was pretty much the only open source, web-focussed, runtime-typed language with a package manager fully of goodies. But with Ruby, Python (, etc.) and their very active communities around, it became very easy to switch.
4. It missed academic backing. Having programmers "schooled" in a particular language seems to be important in this world. The winners in this area seem to be Java, C-Sharp, C++, C, Python and to some extend Haskell; Perl never managed to enter this league (and does not seem very fit).
For a while at least, Perl did find a home in Linguistics. While it was because of the excellent text parsing tools, it makes a strange kind of sense as well, since Perl was designed to be a bit more like a human language and I think Linguists appreciated that. But that's such a small field that the impact was negligible. Most of the modern Computational Linguistic work is done in Java and Python these days, but for a while, many people working in Linguistics came out of their undergrad with at least a passing familiarity with Perl.
For a briefer spell, I seem to remember Perl finding a home in bioinformatics for much of the same reasons. I have no idea what or if that field has moved on to.
For me personally, Perl was the ultimate hacker language when people needed to get shit done and that shit involved munging lots and lots of files in text. But I think these days the world has moved onto other things that Perl isn't any better suited for than some other language (which is then conversely better suited for a bunch of other stuff than Perl).
ADD A TO B GIVING C
That being said, teaching a language, vs using a language to teach can be two entirely different animals.
Perl did have something of a stronghold in bioinformatics (sequencing the human genome etc.), although other languages are catching up.
I love Perl; I hate Perl. I wish Ruby was faster...
The existing perl6 projects can figure out their own branding, because it's clear they are no longer "successors" or replacements for Perl.
The next release in the perl5 series could be Perl 7, similar to what PHP [0] has done to avoid confusing their next major release with a previous, failed effort to create a new major version.
That still forces perl6 to rebrand but won't induce massive confusion.
Larry is a brilliant guy, but (like everyone, really), he's not brilliant in everything and (like most people seen as absolute geniuses, so relatively few people), what he's not good at, he finds so frustrating as to condemn it, and cry foul at the very concept. This helps no one.
I don't know how to teach someone humility.
Anyways beating a dead horse.
This is not a reality with which I am familiar. I like the idea of APL; I even did some, years ago, but this feels strawman-y to me. Even in the J/K/APL crowd, the running joke is readability.
It's kind of sad that functional programming lanuages have regressed and treat higher dimensional tensors so poorly. Libraries like repa for haskell are nice, but they don't approach the flexibility of APL.
Wasn't "Perl 6" just a tentative spinoff from "Perl 5.6", and didn't Perl programmers start unofficially refering to subsequent versions of Perl 5.x as "Perl x", i.e. Perl 5.7 as "Perl 7" and the latest version as "Perl 20" ? Better make official how Perl programmers are speaking anyway and call the next version Perl 21.0
No. Perl6 is a complete redesign of the language, unencumbered by backwards-compatibility. One of the design goals was to make it extensible on as many levels as possible (proper specification, multiple backends, meta-object protocol, pluggable syntax, macros, FFI, ...) so that another rewrite won't be necessary in the foreseeable future.
didn't Perl programmers start unofficially refering to subsequent versions of Perl 5.x as "Perl x", i.e. Perl 5.7 as "Perl 7" and the latest version as "Perl 20"
Not that I'm aware of, but I'm on the edge of that community.
This is certainly a annoyance compared to e.g. Ruby. It's getting easier to just always use references [0], but I haven't been using Perl much for a few years and am not sure if this is still considered experimental.
[0] http://search.cpan.org/~rjbs/perl-5.20.0/pod/perl5140delta.p...
