I recently discussed ITA's use of Lisp in solving cheapest route problems in the air travel industry.  I was talking to somebody today about that and recalled another instance of using an "alternative" language in the travel industry.  I met C. Andrew Shepp back around the same time I saw the ITA demo, and he had a set of tools for travel agents written in APL, of all things.  The problem space was a bit different, he was screen scraping off the CRS terminal formats, but it seemed relevant.  As far as I can tell, his company's not active anymore, probably a victim of the general downsizing among travel agents.