Perl Myths and Mongers in Dublin

Last weekend I went up to Dublin to speak at OSSBarcamp. I took the train from Limerick on Friday so I’d already be in Dublin the following morning, without having to get up at the crack of dawn.

Aidan Kehoe and I had a very small but interesting meeting that night. Their first since 2004! Our wide-ranging discussions that night included me trying to understand what led to flounder instead of flourish. I think a key factor was the (implicit?) expectation that members should make technical presentations.

Living in the west of Ireland there aren’t enough local Perl users (that I’ve found so far) to have a viable Perl Mongers group. So I setup the Limerick Open Source meetup instead.

Here’s what worked for us: We sit around in a quiet comfy hotel bar and chat. Naturally the chat tends towards the technical, and laptops are produced and turned around to illustrate a point or show results of a search, a chunk of video etc. There’s no set agenda, no declared topics, and no presentations. And yet, I think it’s fair to say, that everyone who’s come along has learnt interesting (albeit random) stuff.

I’d like to hear from perl mongers, in groups of all sizes, what kinds of balance between the social and technical aspects of Perl Mongers meetings works (or doesn’t work) for you.


At OSSBarcamp I gave a ~15 minute ‘lightning talk’ on Devel::NYTProf in the morning, and a ~50 minute talk on Perl Myths in the afternoon.

The Perl Myths talk was a major update to my previous version, now over 18 months old, incorporating lots of updated graphs and other fresh information.

There is so much happy vibrant productive life in the Perl community that updating the presentation has been lovely experience. I keep having to revise the numbers on the slides upwards. There are lots of great graphs and they’re all going upwards too! (Many thanks to Barbie for the great new graphs of CPAN stats.)

I’ve put a PDF of the slides, with notes, on slideshare. Best viewed full-screen or downloaded.

I made a screencast but I think I’ll hang on to that until after I give the same talk, updated again, at the Italian Perl Workshop (IPW09) in Pisa in October — I’m really looking forward to that! I’ll make another screencast there and decide then which to upload.

After OSSBarcamp last week, and before IPW09 in late October, I’ll be flying to Moscow, visa permitting, to give a talk at the HighLoad++ (translated) conference. I’ve never been to Russia before so that’s going to be an amazing experience!

TIOBE Index is being gamed

It is sad, but inevitable, that the TIOBE index of programming language “popularity” (sic) would be gamed.

Once you start measuring something, and advertising the results, people with an interest in particular outcomes naturally start to look for ways to influence those results. (It’s the Observer Effect writ large.)

The fact that TIOBE’s methodology, which I’ve discussed previously here and here, is simplistic makes it particularly open to gaming. Anyone, or any community, with access to many web pages can simply add the magic phrase “foo programming”, where foo is their language of choice, to get counted.

And it seems that’s exactly what the Delphi community did at the end of 20081. They made a concerted effort and it seems to have paid off. (I’d be very interested in hearing about similar behaviour in other language communities.)

Is that behaviour gaming? The author of the post who exhorted is readers to “Update your Delphi related blog or site to say Delphi programming on every page in visible text (update the template). Stand up and be counted. You can make a difference!” doesn’t seem to think so, as he also said “I am not suggesting we game the system, just that we help TCPI get an accurate count.

An accurate count of what, exactly? That’s always been the fundamental question with TIOBE. It should be obvious that most web pages that talk about “delphi programming” wouldn’t actually contain the phrase “delphi programming”. The same applies to every other language. That’s the paradox at the heart of the TIOBE Index. And yet, somehow, TIOBE seem to think that counting pages containing the phrase “delphi programming” lets them claim that:

The ratings are based on the number of skilled engineers world-wide, courses and third party vendors.

Eh? How can they possibly defend that claim? Certainly their documented definition doesn’t support it, or even mention it.

I presume they’re thinking that CV’s, job postings, and adverts are most likely to contain the magic phrase. It should be obvious, again, that the number of CV’s, job postings, and adverts referring to a given programming language would naturally only be a small fraction of the total web pages referring to the language. (And only distantly related to the “popularity” of a language.) Yet that “small fraction” is what TIOBE measure and make bold claims about.

The fact that TIOBE is making a comparison based on a small fraction makes it even more troubling that TIOBE CEO Paul Jansen appears to support language communities changing their pages to include the magic “foo programming” phrase. In an email quoted on he says:

For your information, I think your action has already some effect. Tonight’s run shows that Delphi is #8 at this moment. There is a realistic chance that Delphi will become “TIOBE’s Language of the Year 2008″

He’s endorsing the artificial insertion of the magic phrase. Clearly this distorts the TIOBE index in favour of language communities that infect as many pages as possible with the magic phrase.

That sure seems like an invitation to game the system! It’s likely to lead to other language communities doing the same, and so to further devaluation of the TIOBE Index.

(For alternatives to TIOBE you could look at sites like, James Robson’s Language Usage Indicators, or my popular comparison of job trends blog post with ‘live’ graphs.)

I have, on a couple of occasions, used the phrase “perl programming” in blog posts for my own amusement, and linked it to my original TIOBE or not TIOBE – “Lies, damned lies, and statistics” post. I haven’t suggested that others do the same. TIOBE’s endorsement of artificial insertion changes that. Now it seems like we’re going to get a dumb “race to the bottom” to see which language community controls the most web pages.

If, as a result, the TIOBE Index is affected significantly, then I simply hope they’ll drop their pretentious claims and state clearly exactly what they’re counting, how they’re doing it, and what it means: not much.

1. Many thanks to Barry Walsh for his blog post that alerted me to this.

Concurrency and Erlang, and more

Just found the excellent Concurrency and Erlang page by André Pang. (I’m not sure how I got there, but I started froma post by Pedro Melo.)

The page has great links to quality articles and resources with commentary and context for each. It also includes sections specific to C, Objective-C, C++, Java, Python, JavaScript, and Haskell.

What, no Perl? Well, using threads in Perl 5 is rather painful. I’ve never had to use threads with Perl 5 (beyond making DBI thread safe a few years ago) and I’d be happy to never have to.

On the other hand, I believe people are using threads successfully, though I’ve no handy links for you beyond pointing out that CPAN offers a number of solid Thread:: modules.

All this reminded me that I’d never got around to reading Parrot’s Concurrency design document. So I did. I liked it as a statement of direction, though it’s a little thin on the interaction between schedulers.

I couldn’t find many interesting links discussing both Parrot and Erlang. An O’Reilly Radar post called Parrot and Multi-threading from September 2007 was hopeful.

I’m still wondering if Parrot could act as a virtual machine for Erlang. I think that would be a valuable test case for the quality and scalability of the concurrency design.

TIOBE or not TIOBE – “Lies, damned lies, and statistics”

[I couldn’t resist the title, sorry.]

“Figures often beguile me, particularly when I have the arranging of them myself; in which case the remark attributed to Disraeli would often apply with justice and force: ‘There are three kinds of lies: lies, damned lies, and statistics.
– Mark Twain

I’ve been meaning to write a post about the suspect methodology of the TIOBE Index but Andrew Sterling Hanenkamp beat me to it (via Perl Buzz).

I do want to add a few thoughts though…

The TIOBE Programming Community Index is built on two assumptions:

  • that the number of search engine hits for the phrase “foo programming” is proportional to the “popularity” of that language.
  • that the proportionality is the same for different languages.
  • It’s not hard to pick holes in both of those assumptions.

    They also claim that “The ratings are based on the number of skilled engineers world-wide, courses and third party vendors” but I can’t see anything in their methodology that supports that claim.
    I presume they’re just pointing out the kinds of sites that are more likely to contain the “foo programming” phrase.

    Even if you can accept their assumptions as valid, can you trust their maths? Back in Jan 2008 when I was researching views of perl TIOBE was mentioned. So I took a look at it.

    At the time Python had just risen above Perl, prompting TIOBE to declare Python the “programming language of the year”. When I did a manual search, using the method they described, the results didn’t fit.

    I wrote an e-mail to Paul Jansen, the Managing Director and author of the TIOBE Index. Here’s most of it:

    Take perl and python, for example:

    I get 923,000 hits from google for +”python programming” and 3,030,000 for +”perl programming”. (The hits for Jython, IronPython, and pypy programming are tiny.) As reported by the “X-Y of approx Z results” at the top of the search results page.

    Using google blog search I get 139,887 for +”python programming” and 491,267 for +”perl programming”. (The hits for Jython, IronPython, and pypy programming are tiny.)

    So roughly 3-to-1 in perl’s favor from those two sources. It’s hard to imagine that “MSN, Yahoo!, and YouTube” would yield very different ratios.

    So 3:1 for perl, yet python ranks higher than perl. Certainly seems odd.

    Am I misunderstanding something?

    I didn’t get a reply.

    I did note that many languages had dipped sharply around that time and have risen sharply since. Is that level of month-to-month volatility realistic?

    Meanwhile, James Robson has implemented an alternative, and open source, set of Language Usage Indicators. I’m hoping he’ll add trend graphs soon.

    Update: the story continues.

    Perl and Parrot – Baseless Myths and Startling Realities

    I was recently invited to speak at the Irish Web Technology Conference (26-29 May in Dublin). I’m used to preaching to the converted but this would be the first time I’ve spoken to a (presumably) more sceptical audience. I agreed speak but haven’t yet been asked to provide an abstract.
    Around the same time I saw a call for participation for XTech (6-9 May in Dublin). So I figured I’d submit a proposal. I’m guessing the audience would be similar so I could develop a single talk for both.
    Here’s what I came up with in the last hour before the deadline: 


    • Perl5 isn’t the new kid on the block. Perl is 21 years old. Perl5 is 14 years old.
    • Perl5 hasn’t been generating buzz recently.
    • Perl5 has just been getting on with the job. Boring but true.
    • Lots of jobs, in fact. I’ll show you the surprising scale of the Perl jobs market.
    Massive Module Market:
    • Vibrant developer community
    • Over 14,000 distributions (53,000 modules) with over 6,400 ‘owners’ (lead developers).
    • Thousands of releases per month to hundreds of modules.
    • CPAN has over 360 mirrors in 51 regions (TLDs)
    • Automated testing applied to all uploads by the CPAN Testers Network: 61 different platforms and 20 different versions of Perl.
    • I’ll take you on a lightning tour.
    • Five years after Perl5.8, Perl5.10 is now out.
    • Packing a powerful punch for power users.
    • I’ll show you the highlights.
    • An advanced virtual machine for dynamic languages.
    • Advanced capabilities with blinding speed.
    • Already supports over 20 languages.
    • I’ll give you a quick overview.
    • A new generation of programming languages.
    • Advancing the state of the art in powerful practical languages.
    • specification not an implementation.
    • Multiple implementations exist already.
    • Generating code for multiple backends: Parrot, Perl5, Lisp, JavaScript.
    • Sharing a common test suite of almost 20,000 tests.
    • Perl6 is written in the best language for the job: Perl6!
    • I’ll demonstrate Perl6 code for you.

    And I’ll do all this in 40 minutes. Fasten your seat-belts!


    The IWTC session is 75 minutes so I figure I can write a good presentation by the end of February for that and then distil the essence down to the 40 minute session I (hope to) have at XTech in May.
    I’d welcome any comments on the abstract. Especially anything worth saying, or ideally showing, to a relatively perl-sceptical audience.
    I don’t want to get into a  language comparison debate. Perl can stand on it’s own. But I do want to show that for any cool gizmo that language Foo has, that Perl has something similar. An obvious example is “Ruby has Rails, Perl has Catalyst (and others)”. That’s easy to say but doesn’t carry much weight. For each of those I’d really like great example.
    For Catalyst a big-name-web-site built using it would do. Other cool gizomos need other killer examples. Got any suggestions?
    Looking at it the other way, perl has a few cool gizmos that might be worth a mention if time allows: perltidy springs to mind. What others can you think of? And what parallels do they have in other languages?