est31

Fuchsia is the most serious OS that has significant components written in Rust at this moment, so this is pretty neat!

steveklabnik

Depends on how you define "serious"; for desktop-ish, sure, but for embedded, for example, the Hubris OS we've written at Oxide is a key component of the entire company's product. There's a lot more diversity in the embedded space in general.

est31
TIL about Hubris, very cool! One could probably also mention the bunch of hypervisors, as they run on the bare metal as well, and maybe Tock, and I'm probably unaware of a bunch. Rust is definitely a hot language when it comes to OS development, which is really great.

I've cloned hybris [0], it seems to have 48k lines of Rust source code. Maybe there are other components that I'm missing. Fuchsia [1] on the other hand had 2.1 million lines of Rust in Dec 2020 [2], and according to tokei has 3.3 million as of now (8b51db9e2b809, March 28 2022), more than it has C++ (2.2 million) and C (366k) combined.

For comparison, a full check out of the rust-lang/rust repo with all the submodules which contains rustc as well as tools like cargo, rustfmt or clippy, and their test suites, contains 2.1 million lines.

But yeah you can come up with several definitions of "serious". Is an OS that an entire company bases its revenues on more serious than a research project that some call as a way to maintain senior developer retention, but may one day replace components of one of the most deployed end user operating systems in the world?

[0]: https://github.com/oxidecomputer/hubris

[1]: https://fuchsia.googlesource.com/fuchsia/

[2]: https://www.reddit.com/r/rust/comments/k9djda/expanding_fuch...