OCaml is an object oriented language, yet people who do real work in OCaml (and yes, there are such people, and their work is very real) appear to rarely use the object oriented features at all. The reason seems to be that the combination of a fancy module system with the standard trappings of higher-order, typed functional programming (algebraic data types, pattern matching, and the like) solves most of the same problems as OO in ways that OCaml users find easier to use.