I think it's going to be really hard to do the study in a rigorous way. Solid data would be nice, though. Then we could stop guessing.

My best try at a data point is that Lisp was #4 on the TIOBE index back in the 1980s. Now it's on the fringe. I assert that people had been exposed to Lisp, it was widely used. It became less and less popular. It's not that industry didn't know Lisp; they knew it and turned away from it.

Of course, the big flaw in my argument is the growth of the industry. A huge number of new people came in. Did they know Lisp, even at a college level? Maybe, maybe not.

My counter-argument to that is that industry knew Lisp, even if the new programmers didn't. If industry wanted them to learn Lisp, it could have made knowing it a job requirement, or trained people.

> My best try at a data point is that Lisp was #4 on the TIOBE index back in the 1980s.

Unlikely, given that TIOBE the company wasn't founded until 2000, and the TIOBE index is based on web search engine results, and there weren't any web search engines, or a web for them to search, in the 1980s.

https://www.tiobe.com/tiobe-index/ has historical data going back to 1988. (Presumably they used a different methodology for the older data.)

But I remembered wrong. They list Lisp as #2 in 1988.

In the realm of personal computing, Lisp was nothing in 1988. "Nobody" was doing any Lisp programming for affordable consumer hardware. Lisp had almost no mindshare among people who got started in computing with 8 bit microcomputers in the late 1970's and 80's and who moved on to PC's and Macs. (Speaking of Macs, there was maybe the OpenMCL exception there.) Lisp was something that you heard about that ran on "big iron" owned by exclusive institutions. Lisp machines count as that, basically.

Macintosh Common Lisp was mildly popular on Macs. Apple used it themselves in several projects and eventually bought it, hired the team and sold it into their developer channel.

Another interesting offer was MacScheme.

LeLisp had a Mac version and it was used to implement an interface builder, which was demoed to Steve Jobs, who then hired the developer to create a version for NeXT.

Both Symbolics and TI delivered Lisp Machine boards for the Mac II.

Procyon developed a Common Lisp with UI for both Macs and PCs.

ExperCommon Lisp was another Lisp for Macs.

XLisp had Mac version.

On the PC there were numerous Lisp implementations.

Agreed it would be really hard. I do want to underscore I'm interested in the question. And I don't know which way I expect it to go.

My personal hunch is that lisp was just too expensive when most industry took off. In near every way. C compilers being basically free is a ridiculous advantage. Yes, there are free lisp implementations today. However, early mover advantage is working against them, now.

I'd agree that Lisp was too expensive when things took off. Not just in terms of compilers, but also in terms of hardware requirements. C was a better match for the tight memory of the day.

My personal hunch about the experiment (based on nothing more than my intuition) is that people think differently, and that Lisp's syntax is a good match for how some people think, but not for how the majority of programmers think. But as I said, that's just my current intuition. My intuition a year ago, for example, was different...