You might find this interesting: https://ocaml.janestreet.com/?q=node/61

TL;DR: Jane Street is a quantitative trading firm whose language of choice is OCaml and has several people programming in it full-time. Besides experiencing the commonly-cited advantages of FP (productivity, expressiveness, local reasoning), they also found it highly performant, useful for rapid prototyping and resilient to changing requirements.

By "several people programming in it full-time" you mean "everyone who writes code in the company (IT, developers, researchers and traders) writes code in OCaml" right?. Yaron has said (perhaps in that video, perhaps somewhere else) that the founding partners (who were voice traders, not programmers) learned OCaml as their second programming language, after VBA. The language pervades the company.

That's right. All I know is what I saw in that video, though, so you probably know more about this than I do.

Simcorp is another OCaml financial software shop.

I haven't, but the large company I work for has a product partially written in OCaml. I came across it in source control once. I'd guess it's tens of thousands of lines of code, but that's a complete guess.

There's also a list of companies using it here: http://ffconsultancy.com/products/ocaml_journal/free/introdu...

I worked on a Coverity-like static analysis tool product which used OCaml. It used EDG C/C++ parser with FFI.

I worked at a company that based a lot of stuff on OCaml, and since I'm working at Red Hat we use OCaml for a few things. In no particular order ...

* generating code, bindings etc in libguestfs (http://libguestfs.org/)

* analysing Windows Registries for hivex, using ocaml-bitstring

* virt-top

* virt-dmesg

* whenjobs

I used to. We even have an AppStore application written in OCaml.

The search index that backs latexsearch.com is written in ocaml.