to be fair, Slava Pestov appears to be one of those legendary 100x programmers, or perhaps a pseudonym for a group like Nicolas Bourbaki, or some form of non-human being.

I agree. I remember his talk on Factor. I wish people gave enough support back then so he could work on it full-time.

Here is his talk on Factor: https://www.youtube.com/watch?v=f_0QlhYlS8g, back from 2008.

As someone who does a lot of Go, glancing over Factor's syntax in your links makes my eyes glaze over. I'm sure it's perfectly understandable if you take the time to learn it, but languages like Go and Python have the benefit of being nearly immediately understandable for anyone with prior experience

I do love Go for that. Python less so, lots of syntactic sugar, less immediately understandable than Go, IMO, just the list comprehension is less understandable, i.e. I would rather have a for loop when I am reading a reference implementation.

As for Factor, of course, it is a concatenative language. You not only have to learn it, your brain probably has to work in a certain way. Common Lisp vs. Forth vs. Haskell vs. C. They are all at the different end of a spectrum I would say.

I'm not sure what point you intend, since Factor has never been popular. No offense intended to the authors and no shade intended, but I think that's pretty clearly the case.

There are other not-popular languages that build up from scratch. I'd hesitate to go too crazy in assigning causality to this particular characteristic. Being stuck to an existing ecosystem has disadvantages too. But it's not a counterexample to the statement you quoted.

What I am saying is that Factor has had an extensive ecosystem despite it never catching on. I cannot imagine how many libraries there would be were it had a vibrant community and ecosystem. Sometimes I do ponder.

In any case, "Factor has such an extensive set of libraries from just ~4 active developers." is nuts, in a good way.