Those interested in this may find the following articles of interest:

Microsoft goals [edit: err, Microsoft hiring manager vision-casting goal ] to convert 1 billion lines of code to rust by 2030 via automated tooling enabling "1 engineer, 1 month, 1 million lines of code": https://thenewstack.io/microsofts-bold-goal-replace-1b-lines...

DARPA work towards automating converting C code to Rust using a mix of 6 different teams using different approaches: https://www.darpa.mil/research/programs/translating-all-c-to... Feb 2026 Progress report: https://github.com/DARPA-TRACTOR-Program/Reports/blob/main/F...

I hope announcements like this show that Rust is not a fledgling little language that moves fast and breaks things anymore. It's a mature, serious competitor to well established languages like C++ and C#. This is particularly important when trying to compare the experience of using Rust to other languages in the "better C/C++" space like Zig and Odin -- these are much newer and have more rough edges than Rust.

This is very big news, all major OS vendors that also have a role in C and C++ language tooling, now have diversified their options in systems programming languages for greenfield development.

Additionally we finally get some public news about the MSVC integration rumors regarding Rust.

This is from rustconf. A lot of the focus at Rustconf this year has been C++ interop, Python Interop, Javascript interop -- it's no longer about "rewrite it in rust", it's about being part of the ecosystem.

Conversion of legacy nontrivial C++ code bases into Rust (or anything else for that matter) feels like it should be one of the "Millenium problems" for AGI. That and full self driving - including the nuances of gesturing to a human about who's going to reverse in a single lane in a snowstorm.

But if 50% of code can be converted automatically to safe idiomatic Rust? Great. Doesn't sound too far fetched. But yes, there's certainly a long tail here.

The big news here is they've replaced LLVM with MSVC's backend.

I've been writing Rust professionally for the last 5 years (where my first decade of professional experience started in frontend, then moved down the stack TypeScript/Node, Go, C# and so on).

From the perspective of high level application development, I can't see a technical use case for a language other than Rust these days. If wasm worked (and MacOS/Windows/Android/iOS native UI support existed), I would write my backends and frontends exclusively in Rust.

From a low level programming perspective, the high performance of Rust combined with the self-describing type system makes it very ergonomic to use (trying to figure out how a C function signature translates to behavior is a frustrating experience for me).

The thing I have been most saddened about is the lack of professional opportunities for Rust, particularly in Sydney (where I live). I considered moving to the US for the higher salaries and access to Rust roles but recently landed a role here.

What’s the story for Rust-C++ interoperability these days? That’s what kills adoption. Most C++ devs I know like the idea of Rust, but no one is going to go rewrite 30 years of working code. It needs to be something you can incorporate gradually.

If it is a tier-1 language why isn't it supported in Visual Studio?

This makes strategic sense in multiple ways:

1. Rust's memory safety design will help Microsoft improve a gigantic portfolios of products that have been known to have lots of CVEs and 70% of them are memory safety issues, according to Azure CTO Mark Russinovich's talk at RustCon last year.[1]

2. Windows 11's forceful push to retire millions of legacy PC hardware by putting Windows 10 EOL last October was absurd for millions of consumers and businesses. I was literrally helping a S&B having to replace the entire fleet of working PCs simply because Windows 10 of EOL and Windows 11 refused to run on those legacy hardware. Quite honestly those PCs ran just fine! That's why some has been migrated to Linux, in particular to Google's ChromeOS Flex.[2]

3. RAM shortage due to AI boom exhausted the memory chip manufacturers' production pipepline for at least the next 5 years. This means the mainstream PCs sold today will actually have a diminishing RAM size configurations than last year's in order for the PC manufacturers to not drastically raise the product price (or raise prices drastically for high RAM configurations like Apple does). This requires the Windows 11 operating system to be more conservative about RAM usage, Rust can be a part of that.

[1] https://www.youtube.com/watch?v=uDtMuS7BExE

[2] https://chromeos.google/products/chromeos-flex/

So when will we get tier 1 debugging support in Visual Studio?

Good news they adopted Rust as Tier-1 language. I hope their Weather app stop consuming more than 1GB RAM https://www.notebookcheck.net/Windows-11-s-built-in-Weather-...

From the linked Zulip thread (https://rust-lang.zulipchat.com/#narrow/channel/131828-t-com...):

> We are running different workloads including rustc perf suite. In general the runtime performance is on par with llvm.

Not what I would've expected!

Just to clarify, are they 'using' it, or are they 'embracing' it?

I guess the big question is whether they are going to open up rustc_codegen_utc for use outside of Microsoft?

I don't know why I feel the entire software world is going to switch to Rust (more than the others), C++, and Assembly soon.

Especially after the successful Bun 1.4 runtime migration to Rust.

The best C++ interop is just writing C++. Anything else is just wasting time and energy.

Is Microsoft still trying to embrace, extend, extinguish Netscape after all those years? :-)

I haven't made a full switch yet, at this point I'm experimenting more heavily in Rust.

First I built a wrapper for a very simple text editor based on KDEs KTextEditor (basically bindings around Qt C++) then a wasm wrapper around Canvas/WebGL for a basic 2d display list that currently supports sprites and gradient masking.

So far I've been getting away with it just as pure vibe code.

However, the bulk of my primary application is written in Typescript (both client, server and workers). I watched a recent podcast with Anders Hejlsberg (creator of C# and Typescript) where he made a strong argument for why they chose Go over Rust for the updated Typescript compiler. Due to similarities between Typescript and Go, partially based around them both being GC languages, it was just a better fit for a port.

So I am on the fence a bit here but still leaning towards Rust. I'm going to see how far I can push my two personal experiments. I'd really like to get the significant majority of the code I write into two languages (Typescript for anything web-ish and Rust for everything server-ish).

In my time in VC++ and .NET teams, there was only one 1st tier language at MS. It was the one that existed to be whatever Windows wanted - VC++. I've not been there for about 10 years but I haven't heard that anything changed and the blog pretty much confirms that sentiment.

My advice to the Rust team: you're going to get shoved so I hope you're good at shoving back. At least you don't have to worry about stevesi (unless you're with a16z or have kids).

Microsoft is a tier-0 company.

But which GUI toolkit will they use for all their new rust applications?

Visual Rust sounds like a defect but I'm looking forward to it.

What other langs do they consider tier 1? What’s in tier 2?

With certain rough edges like complex traits and Async aside, rust is an S-tier lang in several domains. Of interest:

  - Embedded
  - PC desktop applications
  - Computationally-intense scientific programming. (Chem, structural bio etc)
  - OSes, drivers etc
  - High-performance tasks in general. CPU, GPU, etc.

It’s interesting how things have changed in 25 years. Around 2001, Microsoft was crusading against open source and facing an antitrust lawsuit with Netscape.

Now 25 years later, MS runs its cloud businesses with Linux, and their development in Rust.

I remember an other 1 tier language ms once had. Anyone remember Visual-J? On the other hand if we could code in rust and get windows.forms as a ui it might make sense. MS is burning UI layer faster than one can train on

While literally true, the phrasing of this title will certainly and (IMO) purposefully confuse some headline scanners vs: “Rust Is a Tier-1 Language at Microsoft”.

Fable migrated a Go/Wails project for me to Rust/GPUI and it's so much faster, there is the possibility of Rust to gobble up many more projects.

A MSVC-backend? At this time of year! At this time of day! In this part of the country! Localized entirely within Microsoft?!?

Yes.

May I see it?

No.

Site down, maybe they need port it to use Rust...

They use wordpress

The text is mostly about rustc_codegen_utc; maybe this should be reflected in the title?

Also the use of italics there is rather jarring.

So, Rust.NET?

It’s cool to see rust join C++, C#, and typescript as primary engineering languages. Confusingly there are no tier 2 or 3 languages, just tier 1 at Microsoft

I'm wondering how they deal with long compilation times

As much as I like Rust. Still sad that F# didn't get this much support from their own mother.

Being technically approved by Microsoft is not a proof of quality...

I love how World of Warcraft "gear tier" jargon has expanded into the rest of the world. Pre-Y2K, the pseudo-formal usage of "tier-N" wasn't widespread in the US.

We don't learn Rust at school at all(both undergratuate and gratuate student)

i've never seen such a damning indictment of a language.

started learning rust using the rust programming language book last month!

How the open source turn tables have open source turned

NT kernel rewrite when?

ermm... which are the rust-native libs which enable winrt3.0 native apps?

Link doesn’t work.

What’s a Tier 1 language?

… and they proved you can still write tier-10 software with it

So do we observe overall Microsoft software quality improvement so far?

VisualRust#

who cares. AI will translate brain waves to binary within 5 years.

It is a decompiled language.

If I were the Rust foundation I'd be keeping this to myself right now.

does it mean there is a rust.net?

Waiting for the deluge of Rust cultists....

This thread deserves a meme

Now their broken slop code is at least memory safe.

Rust is now in the Top Ten of TIOBE. Now, TIOBE sucks, but I found that as a general trend plotted over years, it is not that bad. So Rust is definitely having solid demonstrated use cases in the "real" world.

Congrats to the folks involved!

Having previously led Rust at Google, I remember several great cross-company discussions with Microsoft engineers on interop.

Companies with massive C++ codebases use Rust as a pragmatic hedge. C++ as we know it is unlikely to ever become fully memory safe, and unlike C++ standard committee voices who dispute the urgency, major industry players need actionable solutions today.

Because these existing codebases are so vast, Rust must have a viable C++ interop story. However, defining what "good interop" means remains tricky. C++ routinely tolerates aliasing and relies on patterns that violate Rust's aliasing rules. Shared backend infrastructure (like connecting rustc directly to MSVC backends) helps with ABI layout, cross-language inlining, and toolchain parity, but it doesn't solve the core type system divergence.

The fundamental obstacle is type systems:

* Boundaries remain unsafe: Compilers cannot statically verify C++ safety invariants. Crossing the boundary stays in unsafe territory.

* Idiomatic C++ structures often cannot map cleanly into Rust idioms. This forces developers into onerous safety comments or heavy wrapper layers. At some point, application writers will consider serialization / in-process RPC or a full rewrite as a cheaper or cleaner option of getting interop.

Bridging this gap on the ABI level is pragmatic, but pushing Rust's semantics to accommodate C++ edge cases risks compromising "pure Rust" goals. I doubt the broader Rust community will favor complicating Rust's safety model just to smooth over legacy C++ patterns.

To be clear: practical interop is a worthwhile investment, but "seamless interop" needs serious qualification. It will always have hard limits. There will always be friction at the boundary and it will always be a tough sell.

Yet another good reason for me to steer clear of the language.

crazy i like that

I hope this kind of thing means Rust stops making so many rapid breaking changes in th compiler. I've tried it twice, once in early 2021 once 2025. Both times I tried to compile a few random projects I found on the web, stuff like a wordpress fanfic scraper, a software defined radio program, etc.

In 2021 my linux distro I was using had just been released 3 months prior but it's rustc already could not compile 2 of 3 projects due to the use of new features added to rustc in those 3 months. In the SDR case I knew the author and he was able to re-write it in more general rust code and it worked great. In 2025 my linux distro had been out for a couple years. None of the rust projects I tried would compile with my rustc.

Rust, in the past, seemed a very bleeding edge, move fast and break things community. I hope that with more people using it in more places the demographics change and people won't always target latest and greatest. A lifetime for the compiler of at least a few years would make it a very useable language. Adoption at microsoft might help this.

Good, C# is one of the worst languages there is, hopefully they turn it in to tier 18

Sephora is tier-1 at the Clown convention

This is great! Hope this trend will continue in the future; using a memory-safe language should be a top priority imo in context of the coming rogue AI swarms.

M$ choosing Rust might be the strongest argument for picking Go instead

You gotta have balls or be receiving tons of money to publicly celebrate the sloppiest software company of the decade making your programming language Tier 1 internally.

    Embrace.

    Extend.     <-- You are here.

    Extinguish.