That was funny, the comment got upvoted and then downvoted. So perhaps I'm not the only one who would be interested to hear examples of situations in which one would want a Scheme interpreter implemented in Ruby. There isn't much of a rationale in the README. On the other hand, a Ruby interpreter implemented in Scheme would be interesting as an attempt to nail down the ever-elusive semantics of Ruby, if nothing else.

If, as another commenter mentioned, there are "Ruby shops" where one would have to sneak Scheme in through this mechanism, then I guess Ruby has truly reached the mainstream.