I've recently released my Lisp interface to the Unified Medical Language System (UMLS). The UMLS is a meta-thesaurus for medical terminology. The UMLS is large: the raw database is 4 gigabytes of ASCII data containing nearly 900,000 concepts and over 2 million text strings.
The UMLisp web site has details of some of the interesting techniques employed. There is an online demonstration system that can be used to browse the UMLS which uses XML and CSS for results.
I've spent significant time developing this product. Intentionally, I do not include any documentation. I am hoping to sell documentation and support -- it'll be interesting to see what happens with that.
