Considering that it's been 54 years, and we've yet to find any human being, any at all[1], who can write C without UB, I'd say that writing C in 2026 when there's any other option is basically misconduct and a good case could be made that if the code touches money in any way, then it could be a SOX violation too.
Writing C today is like still writing Cobol. Yes, if you are adding a new type of savings account to your bank, and the rest is in Cobol, then sure write it in Cobol.
Some microcontroller projects may have an ecosystem in C that makes other options harder in practice, but it's still a worthy investment to not use C. There's a reason phone baseband firmwares are moving away from C.
[1] No, not even djb, who people like to bring up.
Undefined behavior does not mean that a language is useless. C is quite nice to write as an abstraction over assembly, and I highly recommend writing C code and thinking about (and checking) what assembly it compiles into.
Also, it is possible to verify that the types of UB that you are referring to do not occur: see the seL4 project, which provides machine-checked proofs for an OS kernel that no execution can reach a state that is undefined by the language specification.
Never said it was useless. But it's pretty damning that literally nobody can write correct code in the language. And my point is that it's been enough time that it can't be seen as a skill issue.
> C is quite nice to write as an abstraction over assembly, and I highly recommend writing C code and thinking about (and checking) what assembly it compiles into.
Absolutely. I think in order to understand programming you need to be able to write C, and be able to read assembly.
C isn't "high level assembly", with the whole discussion about the spec talking about the abstract machine, but one does not need to be a C language lawyer to be a good programmer.
But to your point about checking the output: That goes for Rust too, and godbolt.org supports Rust too, for this workflow.
So I'm not saying C is useless. But I am saying that if someone were to decide to write their greenfield project in C, then if it plans to have actual users (as opposed to a fun project), then it's basically misconduct.
Cf. Steve Gibson writes his software in assembly, still. Because he enjoys it, and his enjoyment is the primary user. I respect that. But I would NEVER hire someone to write whole applications like that in assembly. Or C.
Sel4?
PDF: https://www.eng.auburn.edu/~kchang/comp6710/readings/They%20...
They aren't being snarky, they're stating a fact. Rust, rounding to the nearest percent, does not exist. It's a trendy language among the Silicon Valley types that HN draws, but 99.9% of the world runs on C/++, OSes written in C/++, and language VMs implemented in C/++. Maybe some day it will change, but hanging around here too much will give you a very skewed idea of how widely adopted it is.
Not as many as there are Python, Java, JS, or C++ programmers. Depending on the survey, C seems to be neck and neck with PHP.
I read the comment the other way, though. The way that says that those other more popular languages are not serious, and NOT for grownups with important jobs.
Edit: actually, Jetbrains 2025 survey has C neck and neck with Rust: https://www.jetbrains.com/lp/devecosystem-data-playground/ . Both "below the fold" and less than 10% of Java.
Think about what Rust software people actually use. Codex CLI, uv, ripgrep, and what else? That's three pieces of software, all development tools for development nerds. Normal people aren't engaging with any of this stuff. Your metaphorical grandma has never used software written with Rust in her life.
> Think about what Rust software people actually use
More and more Chrome, Google, Android, Cloudflare, Prime Video, and phone basebands, parts of Linux kernel, and many other things.
Normal users literally use those all day every day.
Are they 100% Rust? Of course not (well, I don't actually know if some phone basebands are, by now. Naturally very closed source). But they're not 100% another-language either.
If C disappeared from the world, the world would stop, yes. Same with Cobol. Same with Java. Same with C++. Same with assembly.
If I were to guess (completely without basis for my guess) about the number of lines of code that normal users exercise in a normal day (counting each line just once), my bet would be on Java or JS.
Would the Java be able to run without the C code? No. But normal users would not be able to do anything if only C was left. And all banks would be gone.
And in any case C would not be able to do anything without transistors.
- Chrome currently uses https://github.com/googlefonts/fontations to implement its font handling, and text is the main thing on most web pages.
- Windows' DirectWriteCore for font handling is also now written in Rust.
- Firefox's whole CSS engine and GPU 2D rendering engine are written in Rust.
I pointed to a jetbrains study, and then there's a stackoverflow survey[1] showing C neck and neck with PHP at 11th place among professional developers.
We all know there's lots of important C code out there. I don't see anyone going "RIIR!!!" in this thread.
But obviously yes, the 11th place language will have MANY programmers working on it. Not as many as JS by far. But many. In that survey Go is just after PHP. There are also many many Go programmers.
We are not yet at risk of running out of C programmers, like the Cobol situation. Nor do I want us to.[2]
But what point are you trying to make by so strongly defending C and the comment "grownups with important jobs write C"?
[1] https://survey.stackoverflow.co/2025/technology#most-popular... [2] relevant comment: https://news.ycombinator.com/item?id=50187384
Your argument was that the only Rust projects there are are little developer tools, so Rust isn't a production language. When pointed out there are large projects that every day users rely on that use Rust, and not just in corners of the codebase, code that's exercised by approximately all users, you insist it's still not production?
You must not exist, because, rounded to a whole percent, literally 0% of the lives of people in the world are directly affected by you personally
Even big bases as FFMPEG will be ported to Rust, as the porters' repos already use Rust's cc to compile ASM code.
And of course Qemu will be almost a mandatory candidate for obvious reasons.
For instance, quick and dirty SGI Irix emulator:
>Codex CLI, uv, ripgrep, and what else?
RustDesk, Servo/Firefox, tons of gtk4-rs on Gnome and extra tools, Librsvg, CosmicDE (Fedora Atomic with Cosmic can be slightly faster than vanilla Gnome Silverblue), Ruffle, Gopher64, ArtCraft (both the vibecodec cr*p and the AI powered magical multimedia IDE doing crazy stuff which is fine).
Oh, and Harper to sharp your English skills:
https://github.com/automattic/harper
IronCalc looks better than LO Calc performance wise:
https://github.com/ironcalc/ironCalc
Gnome might be a Rust domain tomorrow and nobody would bat an eye. Fedora/RH/IBM can rewrite the Anaconda installer in Rust in no time.