Yes, but they are replacing it bit by bit - I mean, they even started Rust for exactly that purpose. So (without being a huge fan of Rust) the decision to start a "greenfield" browser project in a memory-unsafe language is questionable IMHO...
https://4e6.github.io/firefox-lang-stats/
I don't have an over-time series, but if you're willing to take my memory at its word Rust's percentage has hovered at around 10% for a while now. It seems to have actually gone down recently. Combine that with efforts like Servo being wound down and their team being let go, and it makes me wonder what the future of Rust looks like in Firefox.
If anyone can shed some light on this I'd be interesting to know.
Maybe, but the speed with which SerenityOS, its programs and the browser has been implemented, with so few man-hours thrown at it kinda displays why C++ was chosen over Rust.
There is no comparable project in Rust that demonstrates just how quick you can go from "nothing" to Full-Fledged OS, with applications, with a browser.
Just from the Serenity project (if you've been following it), it looks like C++ is about 10x faster to write performant and safe code in than Rust.
Doesn't that sort of prove my point?
I dunno if you've tried both SerenityOS and Redox - I have, and SerenityOS is just more complete and usable as a daily driver than Redox[1].
Redox developed over 7 years has less functionality than SerenityOS developed over 4 years.
[1] They both have a long way to go before being completely usable as a daily driver, but Redox has a longer way to go than SerenityOS.