Here's a small implementation of Kernel in around 700 lines of Haskell [https://github.com/vito/hummus/tree/master/src/Hummus]. Note that it's not Kernel proper, as it uses delimited continuations instead of the guarded undelimited continuations in the Kernel report, plus there's a few other differences and some bugs.

Anyone looking for a more complete implementation, check out klisp [http://klisp.org]. It's not 100%, but has some stuff not included in the Kernel report, some of it lifted from R6RS. The main thing it's missing which it desperately needs is an FFI.

On the subject of Haskell, what's the shortest Haskell (possibly Haskell subset) interpreter anyone has written?

Thanks for the tip. If it wasn't the end of the weekend, I'd be tempted to break out emacs.