Lisp Symbolics Macivory 3 with loaded software
I believe that the user experience from this system, and similar, can be equally attained with other languages.  Of course, Lisp all the things, and I will agree there is no need of any other language, if that is to be argued .. but!We could surely build an execution environment (which is what this is) with some other of the newer languages, broken as they may or may not be.