Well, most of the big airlines pay ITA software for their Lisp written QPX engine so that it searches their insane pricing data structure to display on that airline's own website.
Does someone know if they rewrote QPX with one of their internal approved languages (Java?) or if they continued to use CL? The Wikipedia page mentions that they offered a simplified API but was discontinued April last year.
I would dare to say they canned the product for good... ^__^;
It is still Common Lisp. Among other things you can tell by their contributions to open source Lisp projects.