Appcelerator Titanium is not a cross-compiler. In fact, you missed this entire category of "native" apps. They embed actual Javascript interpreters in your app

Appcelerator Titanium is not a cross-compiler. In fact, you missed this entire category of "native" apps. They embed actual Javascript interpreters in your app to run your Javascript. They provide bindings in Javascript to native APIs so you can call native code via Javascript.