What I personally hate (and won't forgive Microsoft) about Windows 8 are the missing APIs in WinRT especially for creating executable memory - which is effectively necessary if you want to write a JIT compiler. For further information I refer to Mike Pall's (developer of luajit) rant about this issue: > http://www.freelists.org/post/luajit/FYI-No-JIT-on-Windows-8-for-ARM P. S.: Of course I know that Apple disallows executable memory for external applications on iOS, too. That is one of the reasons why I still don't own any iDevice.