OCaml and Cocoa
I have opened up an alpha-quality version of a bridge between Cocoa (Mac OS X API, Objective C version) and Objective Caml. Despite the common "Objective" prefix, this is not a perfect match, far from it.
In its current state, most of Foundation and AppKit is available from OCaml, but callbacks are not yet implemented (hence any GUI app would be pretty much impossible to write).
At this point I'm looking mostly for feedback; naming conventions are subject to change at any time, until I get to something that is palatable.
The next major step is the implementation of callbacks.
The license is new-BSD style, svn and wiki are at: http://code.google.com/p/objective-c-caml-bridge/