The two places I work both use Ocaml

California State University Northridge
Most of our middleware infrastructure is written in Ocaml (except the
directory server; for now), this includes both web pages using Wdialog,
and traditional middleware layers such as messaging and identity
management, to more low level things such as libraries implementing the
LDAP wire protocol. Remote middleware daemon is a project we started to
solve some of the problems of using ldap directly for identity
management, and ocamldap is a pretty nice ldap library.

http://ocamldap.sourceforge.net
http://www.csun.edu/~eric/ncc-website/opensource/rmwd/rmwd-description.html

Symas Inc.
We use Wdialog for our portal web site