There's a massive difference to multiprocessing: the different sub-interpreters can use a C(++)/Rust extension module to talk to shared state. In the current mu

There's a massive difference to multiprocessing: the different sub-interpreters can use a C(++)/Rust extension module to talk to shared state. In the current multi-processing world, the whole C++/Rust state needs to be duplicated for each process (in the case of our app, this means 5 GB memory usage per core); with subinterpreters, we can share the same C++/Rust state. The `interpreters` API is just the starting point. Compare it with `subprocess`, not with `multiprocessing`. Once subinterpreters are useful, people will build higher-level APIs for them.