I'm neither a Mac nor an iPhone person, but that's pretty cool. I'd like to know what it means in practice, though. So, you can run Ocaml programs on iOS? What about Apple's libraries? Are there any bindings available?
Yes, there is FFI code to expose Cocoa components via OCaml. Support is nowhere near complete for the entire iOS API, and it isn't factored into a reusable library, but it seems most sample apps have a nice wrapper allowing you to specify any additional component interfaces in OCaml itself without dropping down to Obj-C. Works for a nice class of applications right now, including those based on OpenGLES.
I've been waiting a long time for Jeffrey to get OCaml working on iOS7 - this looks like excellent progress. Though this is just an early version, programming in OCaml is so much better than programming in Objective-C so I can't wait to see this project continue.
No, it's not common. Most popular projects are normally hosted on GitHub and managed with OPAM[1]. Also you can checkout some interesting projects here: <https://github.com/rizo/awesome-ocaml/>
There are a number of sample/demo apps here that can be used as a starting point: http://psellos.com/ocaml/ Each app has instructions on how to build from source, etc.
