There is a rustc_codegen_clr which transpiles to .NET

> This project is still early in its developement. Bugs, crashes and miscompilations are expected. DO NOT USE IT FOR ANYTHING SERIOUS.

how can one claim it is tier-1?

Also random student, nothing official from Microsoft.

	▲	debugnik 5 hours ago \| parent \| next [-]
		We thought your Rust.NET comment was somewhat in jest. No, Microsoft isn't porting Rust to .NET, they barely try to support anything other than C# on it nowadays, but the article mentions an internal adapter for MSVC codegen. The project linked above has been posted to HN in the past a few times though.
	▲	pali6 6 hours ago \| parent \| prev [-]
		That project is not in any direct way related to Microsoft