I wonder how much of the original Common Lisp code is still running in the QPX[1][2] part of ITA.

[1] http://lambda-the-ultimate.org/node/2491#comment-38434

[2] https://news.ycombinator.com/item?id=1479107

Once you get the hang of it, it's great. You can do stuff no other site can do. This really asks for some kind of query language. Or maybe there is one?

I feel Matrix is good at finding results, but it doesn't come close to Hipmunk in terms of presentation of those results :-/