Agreed. seatbelt/sandbox-exec has been “deprecated” for many, many years yet it still underlies all of the system’s sandboxing and Claude et al. use it for their own sandboxes. (And so do I — writing seatbelt rules is the only chance I get to write lisp-flavored anything these days.)

This is only tangentially related, but libuv and mio's Windows implementations use the undocumented AFD readiness-based poll interface [1], since there isn't a documented readiness-based interface on Windows. The undocumented interface is now effectively stable since, among other reasons, Microsoft uses Tokio in some of its products.

[1] https://github.com/tokio-rs/mio/blob/master/src/sys/windows/...