[josevalim]

> Erlang and Haskell have been hovering at under 1% for several decades.

I am well aware that I am nitpicking at this point, but putting a restriction on your metric that rules out 99% of programming languages makes the comparison quite limiting. :D

You are ultimately only speaking about languages that are already quite popular, because even languages like Kotlin, Dart, and Swift (all endorsed by billion dollar companies) are hovering around zero by the metric you provided, and I would have a hard time classifying them as a noise. And languages like Go and SQL are still well below the 5%-10% reference point.

[pron]

Obviously 99% of languages never make it at all, but Rust's adoption rate is worse than what the languages at the Go/Kotlin level -- i.e. those languages that aren't superstars but have achieved very respectable success -- had at that age. More importantly, most languages reached their ultimate "tier" by age 10 and virtually all (I think all but Python) have reached it by age 15. As of right now, its adoption doesn't suggest Rust is poised to replace C++, let alone do better. But yes, I agree that its prospects are looking better than Haskell's or Erlang's.

And again, the 5%/10% numbers were symbolic. 10% was meant to represent Go/Kotlin levels of success.