"This document specifies the form and meaning of programs written in the programming language Rust, as implemented by the rustc compiler shipped with Ferrocene. It documents the current understanding for the purposes of compiler validation. As such, given any doubt, it prefers documenting behavior of rustc as included in the associated Ferrocene release over claiming correctness as a specification."
A standardized version of Rust would help the language to mature for more formalized use cases such as safety-critical and hard real-time systems.
It would also help the Rust ecosystem to grow and not be limited by a single organization.