Loopy
Maybe somebody can throw a proper GC at it now so it doesn't require weak references to break leaking reference loops? I don't want to think about how complicated reference management would become in a large multi-threaded application that needs to be maintainable through several years of new features. Such apps already have plenty to worry about in the source code. Java and Python have been able to blend native compilation, immediate deallocation, and GC for a very long time.