> Matrix actually has a good point about the spec extensions though: if your spec is that minimal, nobody is going to be able to agree on what feature set to support.

If that were true, nobody would agree on which Matrix features to support either. What difference would it make if Matrix just-so-happened to be defined as "XMPP, plus the following extensions..."?

> As a Schemer, I can attest to that.

It's one thing to say "the Scheme spec is too minimal; I'm going to make Racket a hard dependency", it's quite another to say "the Scheme spec is too minimal; I'm going to invent my own Python derivative"