You're right, portability of applications is an issue. Though I'd say it's deeper than toolkits, deeper than libraries or frameworks, and deeper than languages

You're right, portability of applications is an issue. Though I'd say it's deeper than toolkits, deeper than libraries or frameworks, and deeper than languages. It starts in the interaction model. I like what Apple is doing with this (think iWork on the Mac and iWork on the iPad), and I'd hate to see that go away. You could argue all you want that the Windows 7 desktop is not that different from the MacOS 10.5+ desktop, not that different from the Web interaction model; you'd have your points and I'd have mine. My main one is that if it feels different, then it is (a bit of a duck-typing mindset, understandably). And if it is different, then it requires fundamentally different software application, even if the problem domain you're tackling is the same. Some low-level things might be portable, but many won't be; whatever's closer to hardware (audio, storage, search, video, rasterization) is more likely to be reasonably and defensibly portable. Everything else I want to be specific to the interaction model of a given device, within reason. Objective-C and OCaml are fairly high-level, but that's not what they are going after here; they are going after the likes of WPF and Cocoa and Cocoa Touch, general-purpose high level libraries of code. And that's exactly what I would not want to ever happen. Let's not go there. Because it would be terribly silly.