Firefox is a special case, since it uses unreleased experimental features of the Rust compiler. IMHO it's unnecessary, but that's their choice (they get some ni

Firefox is a special case, since it uses unreleased experimental features of the Rust compiler. IMHO it's unnecessary, but that's their choice (they get some nice-to-have features). Most of the Rust ecosystem targets the latest stable release of the compiler. Updates for Rust users are very easy and reliable. It remains compatible with sources since 2015, so there's generally no obstacle to upgrading. Changes between versions of Rust are very small, often just new functions in the standard library or some compiler flag. But people use them as soon as they're available, so everyone else has to use latest stable Rust as well. This clashes with policies of many Linux distros that keep years-old software and prefer not to touch it. This is more of a culture/policy problem than a technical one. Rust wants to be up-to-date like Chrome, distros update Rust like Internet Explorer.