>>20
I think Guile is a bit overrated. It seems to deviate from the standard and to keep its deviations due to legacy systems. Yet at the same time as deviating from the standard it doesn't seem to offer much in the way of functionality that goes beyond the standard and SRFI. In contrast while Racket deviates from the standard perhaps more than any other programming language which might be called a Scheme, much of the functionality and deviations are very interesting.