Fuzzy matching in MySql (Levenshtien Distance)

http://stackoverflow.com/questions/4671378/levenshtein-mysql-php

International Standard Industrial Classification

http://unstats.un.org/unsd/cr/registry/isic-4.asp

An alternative is S&P's MSCI

http://www.msci.com/resources/pdfs/MK-GICS-DIR-3-02.pdf