A while back I saw a toy tcl interpreter in 550 lines of C called 'picol'. I was looking for a simple language to implement in haskell, so I made my own toy tcl interpreter. It was surprisingly easy to make, thanks to the magic of Haskell and Bytestrings. :) It handles a few things incorrectly, and it is not feature complete, but I thought maybe somebody else might find it interesting. For the record (though it means nothing), my interpreter is about half the size of picol and runs about 30% faster in the few tests I've run, despite having a few more features. (it was certainly less than half the size of picol, but I keep tacking on functions when I get bored). Anyway, you can check it out at: http://code.google.com/p/hiccup/ I plan on making it more complete and faithful to tcl, but I'm branching into a different project for this one. However, any suggestions to make hiccup more efficient, elegant, or correct are certainly appreciated. Cheers, Kyle