dsandler.org/wp

Real-world lisp as used in modern flight reservation
systems. (I think Orbitz is using this already; that doesn’t give them
the right to have poor customer service, though.)

Excerpt: “We can do 10 seconds of Lisp computation on a 800mhz box
and cons less than 5k of data. This is because we pre-allocate all data
structures we need and die on queries that exceed them. This may make many
Lisp programmers cringe, but with a 250 meg image and real-time constraints,
we can’t afford to generate garbage. For example, rather than using cons, we
use ‘cons!’, which grabs cells from an array of 10,000,000 cells we’ve
preallocated and which gets reset every query.”