Microsoft has designated Rust a 'Tier 1 language,' providing strong support as an important language alongside C++, C#, and TypeScript.

Victor Chiura, a principal engineer at Microsoft who develops tools for Rust, revealed that Rust has become a 'Tier 1 language' within Microsoft, alongside C++, C#, and TypeScript.

Guest Post: Rust Is Tier-1 Language at Microsoft

https://rustfoundation.org/media/guest-post-rust-is-tier-1-language-at-microsoft/

Rust is a programming language that is gaining popularity in system software where high-speed processing is required, as it makes it easier to ensure memory safety. Microsoft also uses Rust in a wide range of areas, including firmware, drivers, kernels, hypervisors, and microservices.

On the other hand, Windows has a codebase and development infrastructure built up over several decades, primarily in C/C++. To expand the adoption of Rust, a mechanism is needed that allows Rust to utilize the optimization, security features, and debugging environment that have been developed for C++.

So Microsoft developed 'rustc_codegen_utc'. This mechanism connects the code generation part of the Rust compiler to 'UTC', the backend of Microsoft's C/C++ compiler 'MSVC', allowing Rust to utilize the optimizations, security features, debugging and fault analysis tools that have been accumulated for Windows.

rustc_codegen_utc will be available for actual product development from early 2026 and is already being used for building in over 100 project repositories within Microsoft. It has also been stated that, starting with Rust 1.90, it will be possible to build the Rust compiler itself using rustc_codegen_utc.

Microsoft positions Rust as a 'Tier 1 language,' providing comprehensive support for internal development, from compilers and development tools to security measures and actual operation. It is one of the most heavily supported languages, alongside C++, C#, and TypeScript, which are also positioned as Tier 1 languages. Microsoft anticipates that systems combining Rust and C++ will continue to be used for a long time, and states that it will continue its efforts to make both languages easy to use on the same Windows development platform.