I wouldn't consider a "moderness" comparison between CL and Scheme to be useful. They're too different in intent and capabilities. CL has a more-or-less froze

I wouldn't consider a "moderness" comparison between CL and Scheme to be useful. They're too different in intent and capabilities. CL has a more-or-less frozen standard, in the sense that it's unlikely to have an update. Scheme gets updated standards, but they seem to focus on refining Scheme rather than adding "modern" features. Both are very extensible and people do add modern features as implementation extras or libraries. I can't comment about Racket. As an outsider, it appears to be a playground for hardcore CS types to experiment with different programming language features, which suggests it's the most "modern." That's just the impression I get, though - feel free to correct me on that.