> This is an important effort, but it's weird (disconcerting?) to me that something so fundamental as a formal language specification (for a language that adver

> This is an important effort, but it's weird (disconcerting?) to me that something so fundamental as a formal language specification (for a language that advertises safety as a key feature) is being bootstrapped not by the core team, but by a third party. It doesn't feel like that's something you only need "collaboration with" the core team about. I can't think of anything that's more "core". This may be a misunderstanding about what Rust core does: it's a project steering committee. The specification work would have to be done by lang and compiler. The Rust language specification is notoriously informal, as many of the current investors in Rust don't care _that strongly_ about it, at least not in the rigorous sense that certification needs. Major features are built by those investors. Sealed Rust is an initiative to collect the stakeholders in having a proper specification happening. Rust has always evolved on stakeholder needs, with those stakeholders providing the work either through staffing engineers or by funding engineers on the relevant teams and often relies on outside engineering/contribution. This is not _as_ different. So, see it this way: we want Safety Critical Rust to happen. For that, we need some form of specification. We're willing to get a specification funded and contributed in a way that is useful to the project and doesn't tie it down.