When did you first try Lisp (meaning here and throughout the survey "any member of the Lisp family") seriously, and which Lisp family member was it?

It depends a bit upon what you mean by "try." As a high school student in my hometown in the early 1980s, and the son of two educators, I occasionally had the opportunity to visit the nearby university. Upon one such trip, I stumbled across the SRI edition of "The Little LISPer." I was immediately enchanted both by the style and what I intuited as the power of the ideas: it was quite the contrast to Tiny Pascal on my TRS-80 at home! Thankfully, Scheme is a sufficiently small, simple dialect that a non-toy implementation would run on my trusty Model I.

It's worth pointing out that my hometown was Columbus, Indiana, and that the nearby university was Indiana University, a major Scheme school, and home to this day of Dan Friedman, co-author of "The Little Schemer;" Douglas Hofstadter, author of "Gödel, Escher, Bach;" and Raymond Smullyan, author of innumerable charming logic puzzle story books, among other things.

What led you to try Lisp?

The emphasis in "The Little LISPer" on solving problems in terms of simpler versions of themselves, formally known as "recursion." IIRC, Tiny Pascal didn't support recursion, so it was a new concept to me at the time. As I delved more deeply into it (especially once I ended up at IU and got to talk to Dr. Friedman and Dr. Hofstadter regularly), I got the best possible kind of indoctrination into the real power behind the deceptively-simple language. This was not that long after Dr. Friedman had begun making his argument that cons shouldn't evaluate its arguments, so I learned a lot in those days about lazy evaluation, infinitely-long lists, etc. Stuff that you flat couldn't do (and still can't modulo libraries like FC++, Boost Lambda, and/or Phoenix) in any of the mainstream languages.

BTW, I find it fascinating that FC++, Boost Lambda, and Phoenix all do exist for C++.

If you were trying Lisp out of unhappiness with another language, what was that other language and what did you not like about it, or what were you hoping to find different in Lisp?

Scheme is vastly simpler than most languages while simultaneously being vastly more expressively powerful. Common Lisp is vastly more complex than most languages while simultaneously being as expressively powerful as Scheme.

How far have you gotten in your study of Lisp? (I know, that is hard to measure)

Not that hard. I consider myself an expert Common Lisp or Scheme programmer. For essentially the entirety of my post-TRS-80 years, which are greater in number than I like to think about, all of my recreational programming has been in either Common Lisp or Scheme. When people ask me how to learn to be a programmer, I point them to "The Little Schemer" or "SICP," depending upon my assessment of their likely ability, and I suggest they download DrScheme. When I was in MacDTS at Apple (1989-1991), I was the only MacDTS engineer supporting Apple's Macintosh Common Lisp, which they had bought from Coral Software and which was later sold again to Digitool and continues to be available, and one of the best Common Lisp implementations for any platform, ever. I had the great pleasure of making the acquaintance of folks like Bill St. Clair, Andrew Shalit, and Mikel Evins. I also had the distinct honor of being a technical reviewer for Peter Norvig's "Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp;" my name is generously included in the acknowledgments.

What do you think of Lisp so far?

Joel Moses claimed that, by way of contrast to the elegant crystalline purity of APL, Lisp was a ball of mud: you could add anything you wanted to it and it would still be a ball of mud. My own thinking is that Lisp is the cockroach of programming languages: it'll be the only one left after the apocalypse. "Not bad for a dead language."