I Need Closure(s)

Bill pointed out Joel Spolsky saying
"I had to install Lisp in a Box and start working through Seibel's new book on Common Lisp until my brain started functioning again."
What I find interesting is that the number of links to Lisp In A Box on Delicious' lisp tag has really shot up the past couple of days. Expect a newbie mini-flood on c.l.l.

First things first. If there's a Y pun, then you know I must be talking about the Y combinator. Understanding it is on the computer science part of the ol' "Things to do before I die" list. To that end, I got and read "The Little Schemer", and had the same reaction I usually get when reading about the Y combinator, or continuations (another on my "to understand" list). It starts out very simple (cons, car cdr), adds a baby step, another baby step, etc. then they're off on this bizarro explanation that makes no sense to me. Instead of steps A, B, C, D, E, F it's more like A, B, C, W, X, Y; there were some important steps in between that I somehow missed. Is this something I need to eventually conquer to achieve enlightenment, or are they happy, productive Lispers out there who don't understand this?

A related question is Common Lisp and Scheme, specifically PLT Scheme. I've looked at both and prefer Common Lisp to get work done, using emacs and SLIME. Every now and then I look at PLT Scheme, mainly out of IDE envy, and it looks nice. Bill Clementson says it's the best Open Source Lisp. Common Lisp vs. PLT Scheme reminds me of the "even though Python is a better language, Java + IDE combos make you more productive" blog entries I see.

Everyone says the best tool for the job, but for Lisp users I'm thinking that's usually either Common Lisp or Scheme, and other non-Lisp languages. Do Lisp users just stick with one dialect of Lisp, or are there people that use Common Lisp and Scheme for different tasks?

Labels: common lisp, scheme