My own opinion about PL research is that programming is <i>concept serialisation</i>: the programmer has a model of the system (or part thereof) in their head, and the role of the language is to turn that into a byte sequence that is amenable to both being turned into machine instructions and being de-serialised into the heads of other programmers.<p>But different programmers have different abstractions in their heads, and find different things intuitive. That&#x27;s why things like ColorForth and APL exist; to a tiny fraction of people and problem sets they&#x27;re intuitive, to the rest obtuse. I suspect this is why people keep thinking Lisp is going to take over the world despite 30+ years of this not happening.