> Threads run concurrently, in the sense that one thread can preempt another without its cooperation, but threads currently all run on the same processor (i.e., the same underlying operating system process and thread).

By real threads, I mean the ability to spawn a thread in Racket that corresponds to a new underlying operating system thread for that Racket process. Just like you get when you spawn a thread in Java.

Racket places might be what you seek:

https://docs.racket-lang.org/reference/places.html

I want to share data structures built for handling concurrency between threads. I'm less interested in having to "share memory" by message passing between places. Plus, places are more clunky to use compared to Racket's `thread`.

Racket can spawn 'real' threads through the Chez low level API. The new database connection package does just that, for example.