[sanderjd]

To take this thread yet further into self-parody, you might like Rust; it borrows some interesting stuff from Haskell (or really, the ML family), but is actively targeting embedded systems.

Edit: Also, I have heard that Ocaml can be made to work pretty nicely in an embedded environment.

[eru]

You can make OCaml (and Haskell) run on Xen, no need for a full blown operating system. (Not sure if that counts for anything.) The OCaml project for that is called mirage.