One of my favourite implementations is the Javascript implementation in Common Lisp. It translates the Javascript code to Lisp so that it can take advantage of the native compiler. It's very slick.
I think it's quite telling that in all of that text there are actually no real examples as to how a program will actually look like.
Call me old if you like, but I've seen countless of similar "manifestos" covering everything from flight simulators to, yes, programming languages. Only on very rare occasions do they result in something concrete.
(setf (cffi:mem-ref (cffi:make-pointer #xDEADBEEF) :int) #x42)