Jane Street gave a collection of talks at the collection of conferences colocated with this year's ICFP. For me, the most exciting day was the OCaml Users and Developers meeting -- it's always awesome to hear people's experiences writing cool software in OCaml, and there was good news for the community in the form of opam and OCamlLabs, a new lab housed with the Cambridge University Computer Lab, of which I'm sure there will be more news soon.
There were three presentations by Jane Street people at OUD: I gave an introduction to async, Mark gave some from-the-trenches tips on how to debug OCaml programs, and Ron spoke on the Core suite more generally.
The videos and slides are online at oud.ocaml.org. The best thing is that the talks are only a convenient twenty minutes long each!