Err, right - and does Apple provide this "abstraction layer" you speak of? I'd hazard a guess and say no. Or is it simply that their's is a closed ecosystem, w

Err, right - and does Apple provide this "abstraction layer" you speak of? I'd hazard a guess and say no. Or is it simply that their's is a closed ecosystem, with only 1 or 2 devices released a year, and they won't let you run their software on anything else? The fact that Android runs on several hundred different phones from manufacturers around the globe, or that home hackers have managed to get it to run on the most obscure of devices is testament to its flexibility. So I'm not really sure where your argument is coming from. Apple is a walled-garden, with a proprietary OS that literally will only run on their device. Even their SDK doesn't include an actual emulator for the platform - it's just a simulation. I don't have any deep knowledge of phones - but I suspect it's not as simple as "Let's make VMWare for phones". Things like the cellular radio probably require low-level hardware access, the mobile tradeoffs (portability, battery life etc.) probably aren't conductive to virtualising everything, many parts of the silicon probably require binary blobs simply due to how the industry is etc