What Killed Perl?

I heard a fascinating theory a few years ago on the decline of Perl:

In the early aughts, Google SRE recruiting had such a strong, selective focus on A-player sysadmins with Perl expertise that it drained the market of top talent. Within google these people began to adopt, and eventually create and evangelize newer, Googlier programming languages.

In other words, Perl expertise was the skills filter, and Perl itself a technological ancestor of certain modern languages like Go.

I learned and used Perl professionally from around 2005-2015 and experienced first-hand the ossification, fear of change, and lack of innovation in Perl 5 development. It seems all the talent and effort started being wasted on making Perl 6 the bestest, most elegant, most useful programming language in the world. Just seeing the neglect of Perl 5 kept me from ever considering Perl 6 and motivated me to move to other languages.

It's been discussed before, but Python just seemed more straightforward to a lot of people. It had a built-in object oriented model as well when that was the rage instead of the weak default one and dozen modules on CPAN to do object oriented programming. There was generally one way to do something and that was easier to learn than TIMTOWTDI.

As someone that was already working during the dotcom wave, Perl is a tool I would still reach for, given the problem I might trying to sort out, if on an UNIX like platform.

> Binary package managers that chase down dependencies on their own weren’t a thing until the early 2000s, I think?

UNIX package managers started to be made available during the 1990's.

Is it worth learning Perl 5 these days? Maybe to use as a better Bash?

Python.

I think it is due to the fact that Perl has some confusing bits like those variable prefixes ($@%), the lack of function arguments (I know that this has changed recently), not really great error handling, etc and so people started using languages which seemed easier to use like Python.

    @array = ("a", "b", "c", "d"); # @array contains scalars
    $array[0];                     # use `$` for a single element
    @array[0..2];                  # use `@` for an array slice
    @array = ( [1..5], [6..10] );  # @array now contains array references
    $array[0];                     # use `$` still because references are scalars
    $array[0][1];                  # still use `$` even when going multidimensional
    @{ $array[0] };                # use `@` to dereference an array ref to array
    %hash = ( a => "b", c => "d"); # % for hash of key/value pairs
    $hash{a};                      # `$` because you're getting a single scalar
    @hash{"a","c"};                # `@` because you're getting an array of values

    $arrayref = [1,1,2,3,5];       # `$` because we're creating an array reference
    $arrayref->[0];                # `->` because top level
    $arrayref = [ [ 1 ], [ 2 ] ];  # arrayref of arrayrefs
    $arrayref->[0][0];             # no second `->`
    $arrayref->[0]->[0];           # ... but you can use it if you want!

    $arrayref = [1,1,2,3,5];
    $arrayref->@[0..3]; # oh dear. get a real array with an `@` but not at the start!

Already in the very early millennium, jokes like “Perl is an explosion in an ASCII factory” were going around the computer-nerd community, while several publishers were putting out affordable and fun and engaging books to learn Python. No surprise that Perl quickly declined in popularity for scripting. It has been amusing to watch the continual waves of reawakened interest in awk, while Perl seems to remain perennially marginalized now.

As a very long-time Perl developer and FOSS contributor, I think this blog post is incorrect about whether Perl 6/Raku was a factor in Perl's decline. I think Perl 6/Raku did a few things that hurt Perl 5:

1. It pulled away folks who would otherwise have spent time improving Perl 5 (either the core or via modules).

2. It discouraged significant changes to the Perl 5 language, since many people figured that it wasn't worth it with Perl 6 just around the corner.

3. It confused CTO/VP Eng types, some of whom thought that they shouldn't invest in Perl 5, since Perl 6 was coming soon. I've heard multiple people in the Perl community discuss hearing this directly from execs.

Of course, hindsight is 20/20 and all that.

Also, even if Perl 6 had never happened the way it did and instead we'd just had smaller evolutions of the language in major versions, I think usage would still have shrunk over time.

A lot of people just dislike Perl's weird syntax and behavior. Many of those people were in a position to teach undergrads, and they chose to use Python and Java.

And other languages have improved a lot or been created in the past 20+ years. Java has gotten way better, as has Python. JavaScript went from "terribly browser-only language" to "much less terrible run anywhere language" with a huge ecosystem. And Go came along and provided an aggressively mediocre but very usable strongly typed language with super-fast builds and easy deploys.

Edit: Also PHP was a huge factor in displacing Perl for the quick and dirty web app on hosted services. It was super easy to deploy and ran way faster than Perl without mod_perl. Using mod_perl generally wasn't possible on shared hosting, which was very common back in the days before everyone got their own VM.

All of those things would still have eaten some of Perl's lunch.

I spent 10 years in perl and created a lot in it - it taught me a lot about code as a culture,importance of tests, TIMTOWTDI, etc. I think I owe a lot to it.

I found myself defending it more and more online against the folks who were nay sayers - those who complained about its syntax and it's quirks - but that wasn't a problem for unixers who used sed/awk/vim and all the other arcane tools. Perl wawa means to and end and it was the best tool to reach for (the glorious Swiss army knife).

I guess there was an infection period - the brain drain to python and Ruby meant it was harder to find decent quality libs on CPAN anymore as folks would only do things in python. And Yea, while CPAN is still rich, it's not the first hit on Google anymore.

Today, the map-sort-map Schwarzian transform is still the easiest to do in perl than any other language and it helps me whip up the throwaway scripts quick. Wouldn't change the language - I really love it!

Been using Perl since the beginning… essentially every time I needed to write a shell script more than 10 lines long I used Perl … eventually was also using it for web back end stuff too … kind of like duct tape. I still use it today if I need to write more than 10 lines of a bash script.

Personally, back when Perl 6 was harmless vaporware, I never found a place for Perl 5.

For moderately advanced text processing with regular expressions, supposedly its strong point, it was far less elegant and concise than AWK at the low end and far less readable and less batteries-included than Python for more complex tasks involving some integration.

For dynamic web pages, another of the main uses of Perl, PHP was purposefully designed and (while not really good) practical and user-friendly, with plenty of other obviously more robust and serious options (Ruby, Java, later Python, etc.) for more enterprise projects.

Python and Ruby killed Perl.

Before Perl, there was no scripting language that could do systems tasks except maybe shell and tcl, but that's shell is an extremely unpleasant programming experience and the performance is horrid, and tcl's string-based nature is just too weird.

Perl gives you something more like a real programming language and can do shell-like tasks and systems tasks very nicely. Compared to what came before, it is amazing.

But then Ruby and Python came along and checked the "real programming language" box even more firmly than Perl while retaining the shell/systems angle. Ruby and Python were better than Perl along exactly the same axis as the one on which Perl was better than Tcl and shell.

I still use Perl everyday. I know it isn't as popular as when I learned it in the 1990's but I process so many text logs that I find it very useful.

The backwards incompatibility of Perl 6 absolutely killed Perl.

There are many languages still in use today that have all kinds of warts and ugliness, but they remain in use because they still have momentum and lots of legacy things built in them. So being ugly or old isn’t enough of a factor for people to abandon something in droves.

Once you need to rewrite everything, there’s no reason to stay with something you know since you need to fully retool anyway.

As a Perl programmer since v5 was released, the confusion around 6 completely destroyed almost everyone’s enthusiasm, and immediately caused all new projects to avoid Perl. It seemed like 5 had reached the end of the line, and 6 was nowhere to be found. Nobody wants to gamble so many hours of their lives, and the future of their business, on such an uncertain environment.

If Perl 6 had any visible movement within the first few years, it might have survived, but it was a good decade before they even admitted Perl 6 might take longer than expected, and then more time after that before they admitted it should have been a new language. 6 was interesting for language geeks, and they probably did some cool things, but you can’t run a large popular project like it’s a small research project. That completely destroyed all momentum in the community. Perl 5 development only resumed far too late, after the writing was already on the wall.

Both Bill Gates and Linus understand backwards compatibility as a sacrosanct principle. Python only just barely survived the jump from 2 to 3. JavaScript can only survive this because there’s no other option in a browser.

About a dozen years ago, I noticed that the young all seemed to know Python, and did not seem to know Perl. Given that they would be maintaining such code as I wrote and was worth keeping around, I moved to writing in Python. Now when I write Perl, I do silly things like forget semicolons.

Perl can be very well written. I deeply regret not encountering Perl Best Practices when it came out.

I still use perl. It's my go to for string parsing (think pipe log file, do something with it and send it to stdout). It's also my go to for anything that I still want to work in 10 years.

I was a happy perl user for a long time, probably until sometime in the early 2010s. I am a sysadmin and perl was a great tool for what I needed to do.

Jim Weirich was a heavy perl user for a long time, and we were both involved in the Cincinnati perl mongers group. He found ruby and fell in love. He thought Ruby would be a good fit for me and we had a long conversation about why he preferred it to perl. It took me a few years, but I eventually took his advice. As usual, Jim was right, and I haven't written any perl since then.

tl;dr: for me, ruby killed perl.

Perl died because more shared web hosting installs supported PHP than Perl.

Perl was the internet in 1990s. People (me) who were doing unix systems work (C, shell, Perl and some DBs and FTPs) could now quickly throw a CGI script behind an Apache HTTP server, which tended to be up and running in many unixes :80 port back then (Digi, HP, Sun, etc). Suddenly I had a working app that would generate reports directly to people's browsers or full-blown apps on the internet! But Perl CGI did not scale at all (spawn 1 short-lived process per request will choke a unix fast), and even after mod_perl [1], that got quickly superseded by PHP, which was really built for the web (of the 1990s). Web frameworks and fastcgi arrived too late to Perl, so internet Perl was practically dead at the turn of the century.

The enterprise, who either did not have any webapps or had tried Perl CGI first and suffered it dearly, got pinged by their sales reps that Java and .NET (depending if you were a IBM, Sun or MS shop) were the way to go, and there they went with their patterns and anti-patterns for "scalable" million-dollar web stacks. That kicked-off the age of the famed application servers that resist up until today (Websphere, Weblogic, etc).

So Perl went back to being a glue language for stitching up data, C/C++ and shell, and that's how the 2000s went by. But by then, Ruby and Python had more sane communities and Ruby was exciting and Python was simpler - Perl folks were just too peculiar, funny and nerdy to be taken seriously by a slick new generation that coded fast and had startup aspirations of the "only $1B is cool" types. Also the Perl6 delusion was too distracting to make anyone event care about giving Perl5 some good love (the real perl keeping servers running worldwide), so by the 2010s Perl was shooting down to collective ostracism, even though it still runs extremely well, fast and reliably in production. By the 2020s the release cycles were improved after Perl6 became a truly separate project (Raku, renamed in 2019), the core has gone through a relative cleanup and finally got a few popular features in demand [3]. The stack and ecosystem is holding up fine, although CPAN probably needs some good tidying up.

The main issue with Perl at this point is that it has not been a target for any new stuff that comes out: any cool module, library, database, etc that is launched does not put out a Perl api or a simple example of any kind, so it's up to the Perl community to release and maintain apis and integrations to the popular stacks on its own, which is a losing game and ends up being the nail-in-the-coffin. By the way, nothing (OSS) that comes out today is even written in Perl. That reduces even further the appeal of learning Perl.

Strangely enough, lately Perl has seen a sudden rise in the TIOBE index [4] back into a quite respectable 9th position. TIOBE ranks search queries for X language and is not much of a indicator, being quite noisy and unreliable. My guess is that those queries are issued by AI agents/chats desperately scraping information so that it can answer questions and help humans code in a language that is not well-represented in the training datasets.

[1] mod_perl was released in 1996, and became popular around 1999: https://perl.apache.org/about/history.html

[2] PHP was released 1994, took off ~1998 with PHP3: https://www.php.net/manual/en/history.php.php

[3] Perl's version changes simplified: https://en.wikipedia.org/wiki/Perl_5_version_history

[4] https://www.tiobe.com/tiobe-index/

It was never about Perl, it was the plethora of alternatives.

Python evolved, PHP had 1000 times more "how to get started" articles, Node happened. And LAMP became the default for noobs.

Even before the Perl 6 insanity dropped, there was a serious underlying problem in the Perl ecosystem: CPAN. There was this module (I don't remember its name, or author) that was pretty important: you'd end up using it if you were serious about Perl.

One day, around 2000 or so, the author/maintainer, a well-known guy in the Perl community, updated the package with an incompatible API. If you used that package, you had to update your code. There was no backward compatibility, nothing. To make things worse, the README stated that it would AGAIN change API in the future, but he didn't know yet what the change would be.

I considered this disastrous maintainer behavior, as I'm sure anyone reasonable would. It was clear I had to stop using this package, and anything else this guy could get his claws on. But there really wasn't a massive outcry that I could see, nobody calling him out for this crap.

That's when I knew I had to stop writing code in Perl. I tried Ruby but found it unstable at that time. Next project I used Python, and never looked back.

Perl is powerful, expressive, and cryptic. Its popularity faded during a time when the popular trend of programming languages was towards simplicity and legibility. C++ gave way to Java and C#.

Also, Perl's strength was text processing in a world where data was moving out of simple columnar text formats and into databases, xml, json, and other formats better represented by object models than lines of text.

I haven't written perl in a long time but I cannot put a finger on why I stopped using it.

It used to be my goto language for quick and dirty scripts that needed somewhat non-trivial text processing.

Anyway, this made me think of the 2008 Damian Connway Perlcon keynote:

    "Temporally Quaquaversal Virtual Nanomachine Programming in Multiple Topologically Connected Quantum-Relativistic Parallel Timespaces... Made Easy"

If you've never seen it it's worth a watch: https://www.youtube.com/watch?v=HzTjPx4NIiM

In all seriousness mod_php killed Perl, or at least struck the fatal blow. In the late 90s I wanted to make dynamic web content, just simple CRUD stuff. The most reliable way to do this was Perl. As long as your hash bang and permissions were correct you could drop a script in a cgi-bin directory and it would work. It didn't matter if the server was Solaris, Linux, or some other Unix. Most hosts that supported Perl also at least had the CGI module installed as well.

It was worth fighting with Perl's syntax because it was the best option for web programming (for random amateurs like myself). Web hosts often didn't have C compilers available so C wasn't an option. TCL was workable but not as prevalent as Perl on web hosts. Same with PHP3. Keep in mind this was an era where you were deploying on machines you didn't on which you didn't have admin access. Most of the time you didn't have shell access on machines you'd deploy on.

As Linux adoption on servers exploded so did the deployment of PHP. It was easy to deploy PHP web apps since they could be readily dropped in your htdocs or public_html directory and be handled by the server. Enabling other CGI outside cgi-bin directories was uncommon.

So by 2000 or so there was no reason to learn Perl to do web stuff easily. You could do it in PHP which was already a templating language. The younger version of me that wanted to do web CRUD stuff bought a PHP book instead of a Perl book. With Python 2's release at that same time if you wanted to do portable non-web stuff you had a much nicer language than Perl available as well.

Nobody we've hired in the last 10 years wants to touch anything Perl.

That said, we re-wrote all of our monitoring scripts in....Bash.

Ugh.

After twenty years of Perl, I switched to Python because I was encountering too many useful frameworks and systems that had no corresponding Perl packages. The last straw was when I wanted to use Mongo and found that the Perl package was unsupported.

Easier to learn languages came along.

Perl stems from a time where COBOL, FORTRAN, and SQL made sense and it was already mind bending for those accustomed to those old languages.

Modern minds can't comprehend Perl.

Raku

I may blog about this next year, again[^1], as I'm working on a project that sort of covers it - not in a way that will answer the question but more observational.

Anyway, I feel Perl's popularity was hugely exaggerated in the mid to late 90s and early 00s. The alternatives were either not there in terms of language and toolchain features, ease of use, "whipuptitude" or whatever, or library support (CPAN was a killer app), or they were too old school or enterprisey. Sysadmins were using it everywhere so it got into all sorts of systems that other languages couldn't without much more faff.

Its back compatibility meant it stayed in those places for a long time. It's still in a lot of those places.

The fall in popularity the last decade or two was more of a regression to the mean, or perhaps below the mean. Many other languages have come along, which have contributed even more to the fall in share.

Yes, yes, Raku (né Perl 6) but I'd argue that also contributed to a lot of really good stuff on CPAN. The Perl 5 core did get neglected for a number of years, as @autarch says, which may have been a factor.

[^1] previously: https://leejo.github.io/2017/12/17/tpc_and_the_end_of_langua...