Obviously any platform is only going to support a few languages natively. But you can always use tools that compile from other languages into the native ones.

Obviously any platform is only going to support a few languages natively. But you can always use tools that compile from other languages into the native ones. What's uniquely overreaching about Apple's new rule is that you can't even do that anymore. On App Engine you can run Java code that has been generated by a compiler that translates Scheme source code into Java. Apple's saying you can't do that. You can't write programs in anything except C, C++, or Objective-C. In theory, anyway. No doubt what they'll do is selectively enforce it just to ban competitive threats like Flash. I kind of wish they were forced to enforce it rigidly, because then they'd start to feel the consequences of doing something so opposed to the way software development works.