I agree with the author that Clojure is great, but I think he overly dismisses Scheme. There's not a standard library for Scheme as a whole, but Scheme is almost an idea, not a language. You have to look at the implementations, and Racket (http://racket-lang.org/) has a great library. I'm always surprised that PLT Scheme/Racket hasn't caught on more.
Also, the whole SRFI project (http://srfi.schemers.org/final-srfis.html) is an attempt to create APIs that are not part of the core language, but are common across implementations that choose to support them.
