I think a lot could be won by reducing complexity of the systems. In modern operating systems we stack too many abstraction layers ontop of each other. Emacs is

I think a lot could be won by reducing complexity of the systems. In modern operating systems we stack too many abstraction layers ontop of each other. Emacs is a great example of a development environment which prevents a lot of complexity because everything is written in one language (Emacs Lisp), functions are available throughout the system, one can rewrite functions at runtime and one can easily pinpoint the source code of any function with the find-function command. It would actually be great to have an operating system as simple, extensible and flexible.