I'd say, a little bit too much jitter, especially in text. Some of the versions for Mathematica, et al. were a little bit closer, IMO.

The text is just a matter of font. The rendering of the graphs look exactly like the original, and that's the hard part.

Edit: as pointed out below, the algorithm was lifted from another version done in Python/Matplotlib by Jake Vanderplas: http://jakevdp.github.com/blog/2012/10/07/xkcd-style-plots-i...

The edit window is now closed, but I realised that the font he uses is Humor Sans, which is based on Randal Munroe's handwriting (the author of XKCD).

http://xkcdsucks.blogspot.com/2009/03/xkcdsucks-is-proud-to-...

I'd agree that the font is too much - it's bordering on illegible for me in Chrome 22 on Win 7.

It is badly hinted and thus badly anti-aliased.