I spent the weekend in Amsterdam, doing ordinary touristy things on the days when I wasn't attending the 2008 edition of the European Common Lisp Meeting. I suspect that most readers of this diary are likely to prefer a summary of the ECLM to the details of my wanderings on the (rather cold) Saturday, so that is what I shall provide.

Walking through the streets of continental cities early (around 08:00) on a Sunday Morning is usually a pleasant experience – everything is closed, most people aren't even yet going to appropriate religious observances, and so you get an unimpeded view of the town, devoid of the hordes that can cause obstruction or aggravation. Unfortunately, Amsterdam is a somewhat popular destination for British ‘stag’ parties; and, indeed, as I was walking down Leidsestraat, two such parties, who did not seem to be the sort to be going either to an appropriate religious observance or to the ECLM, passed each other. Noise ensued.

On arriving at the Felix Meritis, at 08:30 on the dot, I saw a crowd of people, all seemingly with the same idea: to have the first coffee of the day. Fortunately, the doors opened shortly afterwards, and caffeination was allowed to take place. Conversation happened as well, though I can't remember very much of it, not yet having been fully invigorated by the coffee. Mostly I think I explained why I wasn't on the previous night's boat trip: a combination of somewhat tardy registration and a second mouth to feed...

And then the real action, the talks, got under way. Unlike many an academic conference, of of the ECLM's distinguishing features is that the talks are attended by the vast majority of the participants; there's much less of a feeling that people simply attend to chat to colleagues: probably partly because the talks are very much the ‘deliverable’ of the meeting (there are no proceedings or anything like that) but also, I think, because the talks cover interesting ground, and offer perspectives based on a solid amount of experience.

Jeremy Jones (from Clozure Associates) started the ball rolling, with a talk on the production of InspireData: an application built for data visualization in an (American, pre-University) educational context. Jeremy wisely started off with a demonstration of InspireData's features; it contains some very impressive-looking tools, and seems to present them to the user in a sensible way. I haven't tried it or gone beyond the demo, but it looks like a huge advance on, say, using an off-the-shelf spreadsheet program to do data analysis, even (dare I say it) for professionals – though whether it scales up to professional-sized data sets is another question. Some other take-home messages from Jeremy's talk: it is possible to sell shrink-wrapped software, even today, even written in Lisp; having a proper designer on the team (or as your client) can help enormously in producing a usable interface; and having a programmer as your client can be both a help and a hindrance – specify the acceptance process carefully.

Nicholas Neuss followed Jeremy, with a discussion of the FEMLISP framework for solving partial differential equations. Being in a somewhat darkened room, early in the morning at a weekend reminded me a little of my undergraduate days, where discussion of differential equations, fields and the like was par for the course – and the talk took me right back (in a good way). In particular, watching FEMLISP compute the eigenmodes of Lake Constance (surface waves, I think) was entertaining. One difference in kind between this talk and the previous is, I think, a function of the possible ‘market’ for the two tools; InspireData is sold in quantities of the order of tens of thousands at present, while, let's face it, FEMLISP is never going to have that kind of exposure: and so the resources aren't really available to make FEMLISP into a product usable by even other domain experts. Of course, the fact that Nicholas' boss makes a competing product might also have something to do with that...

There followed a talk about large Internet systems, from Stefan Richter. There was an interesting survey during the talk, asking people about the size of their userbase (assuming that they worked on web applications at all). An interesting distribution; certainly applications with millions of users are no longer rare – and Juho showed commendable restraint in not snorting something along the lines of “millions of users?” One other interesting moment was when Nick Levine stopped Stefan, to give him time to write down the long list of libraries that is already available to help build Lisp web applications, from the database to the front-end.

Kilian Sprotte gave the last presentation before lunch, talking about the GL-enabled Patchwork music visual programming system. The presentation unfortunately appeared to be a little bit unrehearsed, and so I'm not sure that Kilian got everything that he wanted to across to the general audience. From my perspective, though, it was sufficiently close to the day job that I could see the point (and catch some of the references; B-A-C-H and so on) – I'll be able to report back to people in the lab, who were asking about it, and maybe we can find some useful musical analysis algorithms in there. Also, it occurred to me that GSharp could usefully provide some import or export functionality for the chord and score editors, maybe through MusicXML, or maybe writing directly into the PWGL notations for notes (tighter couplings are likely to be hard, given PWGL's current non-Open-Source nature.)

Then we broke for lunch; Juho, Nikodemus and I ended up sitting on a table with Hannes Mehnert and Luke Gorrie; among other conversations, we had The Great SBCL Maintenance Debate, and we now have a proposed Plan. (I don't know if any other plans have been proposed, but hopefully soon there will be less uncertainty.) The rest of the lunch break was spent grilling Luke about OLPC and Kathmandu, and eating interesting interpretations of café food. (Pasta arrabiata with beans and squash? I don't think so.)

After lunch, a talk about cheap apartment design architect assistance software: Knowledge-Based Engineering, where in this case the knowledge base is about Norwegian building regulations. The idea of the House Designer product developed at Selvaag is to allow architects to experiment with designs, while tracking that building rules (both governmentally-imposed and the house style) can be accommodated, along with all the necessary pipes and electrics and so on. It was good to see a variety of techniques on display, and I liked the flashes of humour: for instance, that the user-interface group asking for XML descriptions was OK by the Lisp group, but that then the user-interface group wanted to send XML back, and that was not OK. It's good to know that Frode Fjeld has a Lisp job, too; he was solidly namechecked in the presentation.

Then Juan José García-Ripoll came to the stage to talk about ECL design and implementation. There were some wry moments for me there; starting with the observation that he wasn't really a computer scientist at all, but rather a physicist. Also, many of the motivations for the ECL design appear to be direct analogues of some of SBCL's PRINCIPLES : completeness, clean bootstrappability, and preferring maintainability over whizzy features, for instance (I hope I'm not mischaracterizing here; it's possible I'm just evaluating what he said through an SBCL-tinted lens). Given that, I think it's interesting how different the two systems look, maybe just from having different starting points?

After the final coffee break, yet more talks. Marc Battyani, of FractalConcept HPC Platform, talked about using Lisp to program FPGAs for custom high-performance solutions; in particular, applications in the financial world, such as derivative valuations and automatic share trading platforms. (A word of advice to Marc: it's not often that you get to say that you're 1000 times as fast as your nearest competitor, nor that you can process packets faster than the test network can send them to you – so don't let that message get hidden by the constant fumbling for a particular Microsoft Image and Fax viewer window!) The products he has look interesting; best of luck to him for finding a buyer in these more financially-challenged times...

And finally, the pièce de résistance: Kenny Tilton took the stage, to give “a rant on the state of Lisp and Lispniks touching on Algebra software, Lisp libraries, Open Source, Cello, Cells, and somewhere along the way introducing Triple-Cells, animated data modelling with persistence for free”. Unfortunately, it seemed that we weren't going to get this rant; instead, we got a small demo of the Algebra tutoring software, along with some discussion of the dataflow paradigm that Kenny believes is central to all simple applications, and a fair number of sound effects. Nice anecdote about Lisp and speeding tickets, though.

Then it was all over bar the dinner; I chatted to Pascal Costanza and Charlotte Herzeel about the busy workshop season, to Jeremy Jones and Marco Baringer about the (lack of) checkin policy to SBCL's CVS, to Edi about how much Heathrow Airport sucks, among many conversations. As we were about to call it a night, Nick mentioned that the Lambda Express had some spare tickets, and that we could probably hitch a lift back to London by train (rather than by plane to Terminal 5...), so we arranged to meet Dave Fox and his crew the following morning. While on the train, in a spirit of cross-implementation co-operation, we essentially finished the Araucaria from the Saturday Guardian – documentary evidence will be forthcoming. And then it really was all over.