From this HN thread
I gotta say, as a programmer “of a certain age”, a lot of recent advances have an everything-old-is-new-again feel to me. When I first heard of “threads” in the 90s, the term specifically referred to a mechanism for intra-process concurrency that was “lightweight”, i.e. it didn’t have the heavy overhead of forking a new OS process. IIRC they weren’t even preemptively multitasked. Then preemptive “OS threads” became the new hotness and everything using cooperative threads was old and busted. Now a generation has passed and we have “virtual threads” or things like asyncio to solve the problems created by the thing that solved the problems of the thing before.
So now we’re in the position where it’s perfectly normal to run a program with several virtual threads running in a “real” thread in a Java virtual machine running inside a Docker container running on a VM instance in a hypervisor on some giant box somewhere. And if we’re all living in a simulation, then its’ probably turtles all the way down.