Definitely. I use both and nobody uses ISO Prolog and much less pure R6RS scheme. Here's hoping R7RS will be better although for starters it will be divided in

Definitely. I use both and nobody uses ISO Prolog and much less pure R6RS scheme. Here's hoping R7RS will be better although for starters it will be divided in two (small and big). I've been following the process quite closely. R6RS completely failed to establish itself, to this day R5RS is more popular. You'd be hard pressed to find a more divided language than Scheme. As for ISO Prolog, it's not even the most popular standard. It might be in America, in Europe it's definitely Edinburgh Prolog and there's where it's used the most. You guys are giving me great examples of how interpreted languages without a clear spec + reference implementation completely fail to establish a single standard. It can be argued that in the case of Scheme this is a feature, but for something like Wolfram with an existing closed runtime you definitely don't want this.