What does Scheme do well?

What does Scheme do well? What does Scheme (not just RnRS Scheme, but Scheme more broadly) have that no one else has? It isn’t lexical scope – everyone but elisp has that, these days. It isn’t real first-class functions – lots of languages have that too. It isn’t proper tail calls – ML does that right. It’s not advanced compilers for functional languages – those are a dime a dozen. It’s not even first-class control, which a few other languages have. And the REPL – even Python has that.
It’s macros. Since 1986, Scheme has had a macro system that other languages can’t compete with, and haven’t succeeded in matching in the last 23 years. And over those 23 years, Scheme hasn’t stood still – Schemers have developed a vastly more expressive system in which huge numbers of new and powerful language extensions are possible.
So I say, press our advantage. Improve the macro system. Show the programming language world what the real power of “a very small number of rules for forming expressions” is.
That’s not to say that we should neglect the other things that make Scheme a high-quality programming language. They are important, and Scheme needs a community that cares about all her aspects. But this is not the tail wagging the dog – it’s knowing where our strengths lie.

— Sam T.H.
(via R6RS)