A friend of mine drew my attention the welcome message of 4th European Lisp Symposium:
... implementation and application of any of the Lisp dialects, including Common Lisp, Scheme, Emacs Lisp, AutoLisp, ISLISP, Dylan, Clojure, ACL2, ECMAScript, ...
and then asked if ECMAScript is really a dialect of Lisp. Can it really be considered so? Why?
Is there a well defined and clear-cut set of criteria to help us detect whether a language is a dialect of Lisp? Or is being a dialect taken in a very loose sense (and in that case can we add Python, Perl, Haskell, etc. to the list of Lisp dialects?)
Brendan Eich wanted to do a Scheme-like language for Netscape, but reality intervened and he ended up having to make do with something that looked vaguely like C and Java for "normal" people, but which worked like a functional language.
Personally I think it's an unnecessary stretch to call ECMAScript "Lisp", but to each his own. The key thing about a real Lisp seems like the characteristic that data structure notation and code notation are the same, and that's not true about ECMAScript (or Ruby or Python or any other dynamic functional language that's not Lisp).
Caveat: I have no Lisp credentials :-)