I'm playing with keyword extraction algorithms in arc. Yesterday I discovered it was super easy to pull the classic porter stemmer C library (http://tartarus.org/~martin/PorterStemmer/c_thread_safe.txt) through mzscheme's foreign-function interface and into arc. That's not really about the language, but it suggests arc made a really good platform choice. Just by making mzscheme salient it's responsible for getting me hacking more on lisp.