Here’s Dijkstra’s solution in Haskell...
Exactly what it sounds like. Short, sweet, very cool.
This file is both a HTML file and a literate Haskell program. If you rename it to .lhs you can compile it with GHC 6.6. This is a functional, if limited, JPEG decoder. It only decodes grayscale, 8-bit images and is overly sensitive to the options used.
I thought that people might like to learn a little about the JPEG standard. Frankly, you can just skip all the code if you don't understand Haskell.
Very interesting. Hope I have time to digest the whole thing at some point.