Rust does not have any better builtin support for concurrency than C++ - well, it's supposed to be safer, but it doesn't have the kind of fundamental enabling features you're talking about. In fact, most of the tools I can think of that do sound like what you're talking about, like OpenMP, Cilk, etc., are based on C++. (Both Rust and C++ are likely to gain some sort of async/await support in the nearish future, but they're hardly unique in that respect.) Go has a runtime that makes it cheap to spawn lots of threads, but it's not doing any super high level optimization or abstraction either (quite the opposite). I don't know about Erlang.