I'm not familiar with a lot of other dialects, but the information on Racket is terrible. I wouldn't trust any of the other responses. Racket is not an R6RS sc

I'm not familiar with a lot of other dialects, but the information on Racket is terrible. I wouldn't trust any of the other responses. Racket is not an R6RS scheme, it's... Racket. R6RS is an available language/library in Racket, but it's not what you usually use[1]. Racket has also always been a language laboratory, not just a scheme. I'd also wager that it's the most popular scheme used today, maybe even the most popular lisp. [1] The Racket primary language is specified with #lang Racket, R6RS is specified with #lang r6rs. R5RS is specified with #lang r5rs.