Microsoft makes Rust a Tier-1 language and ships rustc_codegen_utc for the MSVC backend

Sources: primary, discussion
Summary: A Microsoft guest post on the Rust Foundation site states Rust is now a Tier-1 language at Microsoft, alongside C++, C#, and TypeScript. It describes rustc_codegen_utc, a rustc backend that generates code through the MSVC code generation stack rather than through a separate Windows-specific path, production-ready since early 2026 and self-hosted since Rust 1.90. The rollout is internal, with more than 100 Microsoft project repositories building with it today and more adopting it each week, and the post makes no claim of availability outside Microsoft.
Why it matters: Hybrid Rust and C++ projects on Windows get one code generation platform, which brings Rust into MSVC hotpatch, ABI, cross-language inlining, and crash-dump workflows without a parallel Windows-specific implementation.
Follow-up: Whether rustc_codegen_utc is released outside Microsoft, and how its output compares with the LLVM backend on Windows targets.