Two other options
Titanium Developer - free community edition - write in HTML/JavaScript - compile with Xcode (requires a Mac or VM)
OpenPlus ELIPS Studio - write in Flex, compile on Xcode (requires a Mac or VM) - they just started charging for their product however.
I think there may be 'toolchain' options for these and some of the others mentioned, which allow you to compile to binary on Windows, and I have seen that you can upload a zip file and have a toolchain style compile done for you online, but this goes against the Apple licensing.
If I am not mistaken, a product such as Titanium that outputs/works with Xcode and does not use any 3rd party / alternative / restricted libraries should be in compliance, because you are ultimately compiling in xcode - normal Objective-C code and libraries.