What do you find so crazy about it? Dynamically typed languages like these can be fast. It has already been demonstrated with Common Lisp and, more recently, JavaScript. Not only that, but LuaJIT has shown that you don't need impossibly complicated techniques or man-decades of effort to get very good performance. In Python's case, the main obstacle to improving the implementation isn't any feature of the language itself, but the giant ball and chain that is the C API.