Roller Coaster Chess

A while ago I drew a comic about playing chess on a roller coaster. Various xkcd readers took up the challenge. Pictured above: Andrew Burke, Chris Ranker, Ryan DowlingSoka, and Chance Brown. To see more pictures of chess on rides, go to If you think you can do better, go for it, and send […]

Perl Appetizers

You may have noticed that the knapsack problem in today’s comic has two solutions. I thought that (spoiler alert!) the 1, 0, 0, 2, 0, 1 solution was the only one, but 7, 0, 0, 0, 0, 0 — seven orders of mixed fruit — also works. Why did this happen? Well, I checked my […]

Kite Photography

Here are some pictures I took by flying a camera-carrying kite over Boston: More at I’m getting a larger kite and hope to make some higher flights. I can’t really plan when I’ll be out there since it depends on the weather, but if you’re nearby (I’m flying them from the MIT athletic field), […]

New Apartment

I’ve finally left Virginia and moved to Boston (the Cambridge-Somerville area). I’m really excited. I try to avoid the teenage-ish tendency to blame everything on wherever I am (“I just need to get out of this town! This place sucks! Hey, can you put on another Simple Plan CD?”). But I really think the Virginia […]

MIT Talk

(Note: Firefox crashed just as I was finishing this post. This is a terse recreation, as I’m about to collapse.) I gave a talk at MIT yesterday (now the day before yesterday). It was wonderful. I had never really done this kind of thing before, but it went so much better than I expected. I […]


There’s some strange text on billboards around New York. I passed these four this weekend: THE ALGORITHM CONSTANTLY FINDS JESUS THE ALGORITHM KILLED JEEVES THE ALGORITHM IS BANNED IN CHINA THE ALGORITHM IS FROM JERSEY It’s clearly a viral marketing campaign and seems to be by I like puzzles like this, but at the […]

Cory Doctorow

There’s no red cape. But, then again, this was taken back in 2004: Photo courtesty Windley (via, of course, a Creative Commons license) Cory Doctorow was the guy who first convinced me to publish xkcd under a CC license, allowing people to share my comics freely. It’s easy to do and was one of the […]