[pjmlp]

While those languages made the concepts mainstream, they weren't the ones coming up with them.

Rust's "ownership model", is a simplification of Cyclone, AT&T's research on a better C, based on mix of affine and linear type systems.

https://en.wikipedia.org/wiki/Cyclone_(programming_language)

Haskell's "Lazy evaluation" was present in Miranda, before all related researchers came up with Haskell as common playground.

https://en.wikipedia.org/wiki/Miranda_(programming_language)

"History of Haskell"

https://www.microsoft.com/en-us/research/wp-content/uploads/...

Java's "Green threads" go back to systems like Concurrent Pascal.

https://dl.acm.org/doi/10.1145/775332.775335

[exasperaited]

And while Smalltalk may be the first quite "pure" OO language, it by no means invented the concept (you could argue it has a purer implementation of messaging but even some of that was in Simula 67, five years earlier).

[Rochus]

Cyclone was indeed a very interesting language. It's always surprising what ultimately prevails.

[pjmlp]

I guess it is always a matter of being there at the right time, or having the luck to spot the right audience.

[AnimalMuppet]

At the right time (or just before the right time). Spotting the right audience (or stumbling onto what a significant audience needs).

And, I think, being better for what that audience is trying to do than existing tools. (But maybe that was implied in your statement.) This also implies adequate tooling and libraries.

And publicity, to reach that audience (though viral is better than corporate).