Employer: Airbus.
Which language did the team choose for the analyzer? OCaml.
It is possible to write OCaml programs that are provably correct.
[0] "Caml language family" http://caml.inria.fr/
[1] "Success Stories" http://caml.inria.fr/about/successes.en.html
[2] "OCaml: a serious contender" http://caml.inria.fr/about/programming-contest.en.html
edit: clarity