you're right in that my argument can be generalized to most (new) programming languages: unless your programming language requires a new VM for some good reaso

you're right in that my argument can be generalized to most (new) programming languages: unless your programming language requires a new VM for some good reason, build it on top of an existing one. when would a new VM be required? well, Erlang for example just could not have been implemented on top of JVM (forget for the moment that it predates the JVM by a few years). BEAM, the Erlang VM, has an overhead of ~500 bytes per process -- try that with JVM. Factor, IIRC, outgrew the JVM very quickly too – though i forget how exactly. most of Lisp's power lies in uniform syntax which manifests itself in Lisp macros. that's not a good reason to write a whole new VM. the reason i talk about "future of Lisp" rather than all programming languages is that at the time i was thinking about Lisp & why it remains unpopular despite being an awesome language.