The ELS last week was fantastic. Nicolas Hafner’s writeup is a good and detailed rundown of the event. I’d like to talk about a few of the things that stood out to me from my perspective.

The attendance was great. 89 official registrants made for a good crowd, even without many of the familiar faces I’ve seen at European Lisp events in the past. I suspect the unfortunate cancellation of ECLM “helped” in this regard. I also talked to a few local Londoners who were at the conference mostly because it was so close. London: hotbed of the Lisp-curious!

89 isn’t a lot of people in an absolute sense, but it was a vigorous and engaged group. I met many new people and enjoyed hearing about their interest in Lisp.

It was an honor to be an invited speaker. I gave the opening talk, “Quicklisp: On Beyond Beta”. (The subtitle is inspired by a book I’ve had to read about 100 times, so far.) The talk is in two parts: a retrospective on some of the trends and changes in Quicklisp and Common Lisp over the past five years, and what I want to do to drop “beta” from Quicklisp. If you’d like to see the slides and the script of the talk, I’ve posted them to github. The talk was recorded, but I’m not sure how or when the video will be made available.



One of the missing features described in my talk, library bundles, is now available in the Quicklisp client. I’m going to write more about it on the Quicklisp blog soon. If you’d like to try library bundles, make sure you’re using the latest client via (ql:update-client).

There were some things I didn’t get to in the talk.

I didn’t talk about security changes for Quicklisp, partly because I’m not completely sure what form they will take. I do intend to offer https access to www.quicklisp.org and the Quicklisp software archives. I also intend to integrate cryptographic signature checking into the client.

There wasn’t enough time to process my raw data for what the approximate “market share” of CL implementations over time. SBCL dominates, but I think the percentages and proportions will be interesting to chart.

And I talked about a few new contributors, but of course there are many new contributors, including eudoxia0, orthecreedence, guicho271828, and more.

Dave Cooper’s demonstration of gendl has evolved. I last saw it in Amsterdam in 2011, and I remember it mostly as a “look, but don’t touch” demo. At this ELS, he was able to get people up and running with the latest Gendl with just one Quicklisp command, and from my view in the back row I could see people starting up Gendl and trying his exercises as he ran through them. Out of the dozens of people who tried it out, only one or two people had problems getting it running. The vast majority were able to try a complex project almost instantly. It felt good to have a hand in making it that easy.

I heard “Thanks for Quicklisp!” a dozen times, and it never got old. It’s one of the things that keeps me energized. People are deriving real benefit from what Quicklisp does and aren’t shy about telling me.



My web of trust expanded when Paul van der Walt proposed, and Christophe Rhodes and others helped execute, a keysigning party. I now have several more signatures on my Quicklisp release signing key.

Baggers’ CEPL demo was a lot of fun to see, and I can’t wait to try it out myself. It’s going to be fun impressing my kids with some simple code producing pretty graphics.

It was also fun to hang out with Lispers before, after, and between the scheduled events. Nick Levine proposed a pre-conference dinner that ballooned to more than 40 attendees, maxing out the back room of a Vietnamese restaurant. The Mercure hotel was home base for many conference-goers, and there were a few late nights in the lounge where we gathered and talked about a wide range of topics, Lispy and otherwise. There were lunches and dinners for meeting new friends and catching up with old.

The weather was fantastic. Spring in London is about three weeks ahead of Maine. The sun shone and it was almost a pity that we couldn’t hold some of the talks outside on the green. It was a joy to walk around the city before and after the conference, sightseeing at all the tourist traps and taking in even just a narrow impression of a city many centuries older than my home.



ELS was a blast. Although I’m still physically recovering from the conference and the travel, it has given me new energy for contributing to the Common Lisp community. A huge thanks to everyone involved with staging it, and to everyone who came up to me and said hello. I can’t wait for the next ELS!