I am looking for a version of Scheme or even LISP that I can use to recover some lost Lisp development skills. Some web capabilities would be nice but not essential.
I've looked at Plt and MIT scheme and, while both look pretty good, the Plt seems to be more feature rich. I've also looked at Lisp implementations but all of the seem quite expensive.
I favor free/inexpensive implementations as this is truly likely to just be occasional hobby programming. What recommendations would you have? Thanks!
Update: Thank you to everyone who answered and/or voted.