I just upgraded some code to Zig 0.16.0 and I am actually really happy with the results. It impacted A LOT of things, but the changes were actually very good and seems to have set the language for a bright future, especially with the new IO mechanism which allows supper efficient code that looks good whether it's implemented single-threaded, multi-threaded or just via an event loop!
If you haven't tried Zig since 0.16.0 was released, I highly recommend having a look. The release notes for this release were huge!!
> especially with the new IO mechanism which allows supper efficient code that looks good whether it's implemented single-threaded, multi-threaded or just via an event loop!
I had some trouble understanding how the async/await mechanism works:
var foo_future = io.async(foo, .{args});
defer if (foo_future.cancel(io)) |resource| resource.deinit() else |_| {}
var bar_future = io.async(bar, .{args});
defer if (bar_future.cancel(io)) |resource| resource.deinit() else |_| {}
const foo_result = try foo_future.await(io);
const bar_result = try bar_future.await(io);
My assumption is that calling io.async using an event loop implementation of IO, it will internally start a "task" (or whatever it should be called) and that the future is a handle to it. So far so good.
The part that I don't understand is what happens when you call future.await(io). Will the IO implementation somehow suspend the current function and resume once the future is resolved? If so, does that mean that every function in zig is a stackless coroutine?
> If so, does that mean that every function in zig is a stackless coroutine?
No and yes.
If you're using Io.Threaded, then the concurrency model is multithreading and calling Future.await will block your thread on a OS futex.
If you're using Io.Evented, then the concurrency model is green threads / fibers and calling Future.await will suspend the current green thread by yielding (swapping CPU state with another fiber).
Zig currently does not support stackless coroutines so today you can't have that, but we used to have them (pre self-hosted compiler), and there's an accepted proposal to bring them back, in which case any function that calls await, or that otherwise has a suspension point, would have to be transformed into a stackless coroutine by the compiler, yes. The plan is for that to happen transparently without requiring an `async` annotation in the function signature, like we already did in the past.
the “(super) efficient” is not there yet. Io is still dynamic dispatch with multiple layers of indirection. afaik it’s slower than before.
the upcoming releases are expected to provide a solution to this “dispatch is comptime-known, but still dynamic” problem, and drop the loses in efficiency.
I believe their plan is using "restricted function pointers", where you can specify that a pointer will only ever be to a function defined in the codebase. I'm pretty sure they also have plans for devirtualization, but I haven't followed super closely.
Hmm in the 2025 talk ( https://youtu.be/f30PceqQWko?si=qZESxMaSyt7fYMfz ), Andrew emphasizes that this approach is more efficient than before- even showing compiled assembly iirc. I guess that was a one-off?
A vtable indirection is essentially free when you're going to perform a syscall. What matters is that the buffer is above the vtable (which is already the case for the current implementation) so that you don't pay for the indirection when hitting the buffer.
Maybe one day it'd be possible to use these new features, but I find myself using `.use_llvm = true` in my zig builds for stability and lesser tested targets.
After having used Zig for a couple of months now I am convinced it is a fantastic tool language. You just pick it up to hack some idea together freely. Every time I hit a wall, I find the creators have thought of it already and offers comfort. But nothing gets in your face how to use the programming language "correctly".
For me it is now the go-to "tinker in my garage" language.
Ugh. This is something I hate about Go. I would be happy to have unused variables generate warnings, but as errors, they turn the toolchain into an adversary.
It's common for me to temporarily comment out a variable's use when developing new code, as I experiment with ideas. It's even more common when working in unfamiliar code, such as tracking down a bug or incrementally adding a new feature. It's an important part of my exploration process.
When I hit Compile at that point, I expect the compiler to build the work-in-progress exactly as it is in that moment. Executing the output allows me to spot check the snapshot's behavior against my expectations and mental model. The compile step also assures me that no syntax errors have crept in while I was focused on the logic flow or general shape of the code.
When a compiler refuses to do its job, and instead barfs up spurious errors complaining about unused variables, it brings my workflow to a screeching halt. In order to make progress, I am forced to abruptly leave my current context to visit all the different places where those variables are introduced, edit them, try again, discover that those forced edits have left more variables unused, and repeat the process until the combative compiler shuts up and does what I told it to do in the first place. By the time I'm allowed to return to what I was doing, my train of thought has been derailed, the bits of logic that I had been juggling have fallen to the ground, and my focus destroyed. And then, once I have recovered my original thoughts and seen the output of my snapshot build, I have to go back and revert all those forced edits before I can resume my work.
What an aggravating, disruptive, and completely unnecessary waste of my time and attention.
I hope Andrew has the good sense to let errors of this kind be silenced or demoted to warnings, perhaps with a compiler flag or debug build mode.
I love Zig and I am generally very happy with Andrew's benevolent dictatorship and the benefits of having one single smart tasteful person in charge of decisions, but the unused variable one really hurts. My guess is that he's seen what a mess C code can be with regard to warnings and so is just totally unwilling to compromise by adding the concept of warnings to Zig. But if I had one wish about the language, it would be for a command-line flag to disable unused variable errors. So much effort has been put into making iteration fast (all this build system stuff, the custom backend, incremental compilation) and then there's just this giant blocker preventing fast iteration on the editing side.
If they wanted the release build to be an error I wouldn't care. Having the current solution be "have the editor automatically change code to include or remove the underscore" is so wrong to me. Just invented a problem that needs tooling to modify source code to fix.
In rust, having unused variables as a warning (but not an error) let's you refactor code, test it and see what is now unused as a result. You can then remove the unused items. Zig requires you to remove the unused items (e.g. with '_ = ...;' which is then something you might forget about) before testing, increasing friction.
Multiline comments are less important, but its still convenient for commenting out large chunks of code. IDEs make this a bit easier when you can press e.g. Ctrl+/ to comment out the selected lines with //, but it doesn't work in all cases.
The friction stops zig from being fun imo. A shame because I really like comptime.
Thanks, there is always a risk of people jumping on replies like that to scream that you are doing it wrong. I just wanted to see how other people do stuff. Hope everyone stays nice.
Not the person you replied to but I leave unused variables as future TODOs. It's a warning in F#. I also often use them for inspecting data in the debugger
My go-to "tinker in my garage" language is Python - lightweight syntax that stays out of your face, batteries included, packages for everything that's not included. What's Zig's edge?
Have you ever thought "Ugh, this bit of Python code is running much slower than I expected on my computer. Wonder if anyone has written a native library for this"? That's probably the closest use case for someone who matches your description -- a language that is much more ergonomic, much more 'modern' feeling (in all the good ways), while still extremely compatible with C.
As for the language itself, it's going to be more verbose than your Python code. Cons: you'll have to spell out a lot of things that you thought were obvious assumptions. Pros: you will be able to look at a page of code and know with a great degree of certainty that there are no hidden gotchas. No monkey patching, no __init__. Basically, it just does what it says on the tin.
And finally, about the std lib and batteries: there's HTTP(S), compression algorithms, hash algorithms, RNG, I/O, the basic data structures you'd expect, JSON. Third-party libraries, if you choose not to vendor, are handled by including the repository url in a file (also automated by a CLI command), and then adding it to the build script (not automated). The `zig` command handles fetching and ensuring sanity, but otherwise assume a bit of elbow grease will need to be involved.
That's actually a great argument for Nim[0]. Easy interop with C, native-speed performance, and a syntax very close to Python in both readability and how quickly you can get something working.
Batteries included, automatic memory management without a conventional GC and metaprogramming - is a really cool combination.
Aggh if only its LSP was better! I have always run into issues when using Helix with it (it kept crashing), and I'm absolutely spoiled by good LSPs in other languages :(
Wish I had the time and skill to actually contribute to the LSP, if you have ever used Nim it's a seriously underrated language.
Araq the Nim creator is working on a rewrite of the Nim compiler called Nimony that'll become Nim 3.
It's making fast progress and will provide the basis for a proper LSP! Nimony already supports incremental compilation and parallel which are key pieces for good fast LSP.
it is my second choice next to Zig and does have a lot of cool features, for sure.
The nice thing is that all these languages feature easy C interop so you can use a C FFI as the interface between them if you want to experiment with, for example, writing a module in Nim
Rarely. Most tinkering tasks just don't have enough heavy duty computation in them to as much as strain a modern CPU. And most of the rest are covered by packages like numpy or pytorch.
For the rare exceptions, I make a C lib and call into it to get my numbers crunched. I get that Zig is a viable replacement for C there. But I don't see it replacing Python.
The argument is that the ergonomics of using Python are worth the squeeze of learning two languages. Are the ergonomics of using Zig really enough to justify replacing Python on the happy path, or would it end up replacing just C?
I find Python extremely unergonomical. Sure, it's nice to read (pseudocode, yay!) and sure, its library ecosystem is beyond amazing.
But... the LSPs I've tried (and I've tried a bunch!) are all atrocious: false positives and false negatives galore. Perhaps I'm spoiled by LSPs from languages with better type systems. Our code is strewn with (to me) mysterious comments such as `# NOQA 1234` which my colleague uses to make his Python tooling work with the codebase. I'm used to languages like Elm or Gleam in which a LSP error means there is an actual problem with your code, and a lack of a LSP error means the code will compile and run.
Even if you are fine with Python's speed, its memory consumption DOES effect things and can be an extraordinary pain when you need to fit the result of your tinkering in any sort of constrained environment.
By the time I’m memory constrained even on my laptop the processing cost of whatever I’m doing has gone beyond shoving it in the first scripting language I can find. Every device I write code on has at least 16GB RAM - most of them are 64 or 128
Not to mention that where heavy computation is required, Python often has libraries that are much, much faster than anything you can quickly hack together in C or Zig.
Only if you doing something thousands of people has done before.
Anything new, even very simple and you are on your own and Python is 100x slower than naive C implementation on many tasks.
Last little project I remember is writing a solver for a puzzle game my friend published. Python just doesn't work at all for such tasks.
I think you are wrong about speed of those libraries as well. In my experience naive code designed for a specific task beats highly sophisticated general code and it doesn't take a rocket scientist to get huge speed-ups over some well established fast library.
And if you really need more performance (or, more often, fast startup times), Go gives you 90% of the speed with 30% of the effort. Rust if you really want to squeeze everything that can possibly be squeezed of that CPU.
that’s not what the benchmarks say about Go, and based on multiple reports, Rust does not scale well into large codebases, which eventually become brittle and very difficult to change
Zig is a return to “no magical effects,” except with reasonable safety
I would be very surprised to see a large Rust codebase being harder to maintain than a large Zig codebase. The former makes it much easier to maintain invariants at scale.
By the time C++ and Java were as old as Rust is today there were thousands of programs that over 1MLOC that had been maintained for at least five years. Rust is a rather old language, yet I doubt there are even hundreds of Rust programs over 1MLOC.
These reports are smoking crack. Rust scales gloriously well into large codebases, and it especially shines when it comes to making major refactorings. Please don't bother speaking about things that you don't understand.
You are entirely right here, you're also incredibly rude. Please don't bother replying when the only thing you're actually doing is being condescending and spreading negativity
Rudeness is perfectly acceptable when it comes to preventing the spread of blithe and thoughtless disinformation. I have no obligation to be polite to people who speak authoritatively on topics they know nothing about. I recommend you spend less energy on trying to defend clueless people by policing the tone of the people educating them, unless you think that polite ignorance is more societally valuable than brusque truth.
I don't think performance has got much to do with tinkering. IMO the real benefit of Zig is you get the flexibility of C with the ergonomics of a modern language.
I like Python as a tool language, and I am very impressed by projects like Micropython, but you always eventually run into a wall. I.e. you are never going to write a compute shader in python, but I assume someone is going to try.
I think the programmer should meet the hardware in the middle, and Python has a few too many layers of indirection to do this well.
> I don't think performance has got much to do with tinkering.
Yes, in general, but also there are cases when you realize you can, idk, parse a CSV file in 0.2 seconds instead of 200 seconds. That kind of improvement unlocks a new level of tinkering.
Zig is low level, so it will certainly not replace your python usage, it is more like a modern C than anything else. There’s a video of a recent interview with Andrew Kelley, if you want to watch it to understand better what Zig is for, it’s on Jetbrains YouTube channel.
No, I get that, but Zig being low level is kind of why I don't get why it would be a good tinkering language?
When I want to tinker, I just want my logic to work, first of all. In 9 cases out of 10 that means going for high level. Even if the resulting code works with low level things like binary structures.
Low-level programming gets a bad name because C has many footguns and the spec leaves much behavior undefined - a fact that implementers use almost adversarially (which I'd support, if the goal was to refine the spec...).
C++ adds more high-level conveniences without actually removing the footguns and undefined behavior (much C code compiles in a C++ compiler).
Zig tries to keep the low-level C philosophy but have things more well factored and well defined. The result is you _can_ tinker in high-level code, yet "drop down" into low-level code as you desire.
(Compared to rust, you get fewer compiler-enforced guarantees, but unlike C the language isn't trying to make high-level code adversarial).
It made me laugh to think of C implementers being adversarial! It can feel that way.
I haven't really used modern C, not sure if it's evolved as much as modern C++, which I feel is a joy to use, and a lot safer. But then I've been writing C++ for decades.
I feel like C evolved from basically syntax sugar for assembly, so that's where all the footguns come from, rather than being actually adversarial.
If some of the things that the C standard left undefined had instead been made implementation defined then the compiler would at least be obligated to do something that makes sense on the target architecture, rather than having license to take the lawful-evil route. (Plenty of architectures have addressable RAM at location zero, for instance.)
For some reason this always brings to mind that moment in Red Dwarf where Kryten, devoid of his behavioural chip, deems it appropriate to serve roast human to his crewmates. "If you eat chicken, obviously you'd eat your own species as well, otherwise you'd just be picking on the chickens!"
Both C and C++ compilers (in fact, they share this part) very aggressively exploited undefined behavior for performance. But I this was certainly not adversarial. Programmers also regularity picked optimizations over safety. I think nowadays the unsafety of C with modern tooling vs the safety of - say - Rust is very much exaggerated.
I would add that Delphi still follows along, enough for an yearly conference in Germany, and that C# since getting Native AOT and the low level programming improvements, is close enough to Modula-3 design.
There is Swift as well, although quite far from Wirthian compile times.
Almost all of my tinkering is “download this thing, cache it (because it’s huge), run a program or a series of programs on it, and package the output up somewhere.” When I’m writing the thing that does the work I’m not tinkering any more..
I've been places, from embedded bare metal to ML AI, and that "embedded bare metal" end is the one place I don't use Python directly in. Embedded bare metal is just ruled by C forever.
Bit of a shame, because C is kind of bad at its job, but nothing else has the "compatible with everything" badge of honor.
The tooling around embedded devices though? Python.
When I want to tinker it’s usually because I want to make something faster than anyone else has done. Does that help illustrate why some might prefer to tinker in Zig, and why your definition of tinker seems a little narrow?
Most of the time "make something faster than anyone else has done" is just not worth doing? Good enough is good enough. Unless it's some super hot path and it's the speed that's the main goal, nothing else. Which is rarely the case.
If you only ever think of tinkering for the purpose of execution speed ninjutsu, isn't it your definition of tinkering that's far too narrow?
No, I’m saying that it’s how I like to tinker. Others have their own ways of tinkering that are just as valid!
I personally think the optimization challenge is fun. I like digging in to low level stuff, reviewing the assembly dumps and processor pipeline architectures. I fail or give up most of the time, but I enjoy learning in the process.
I’m just trying to show how Zig fits my tinkering well, since you said you can’t see how Zig would ever be a good fit for tinkering. I’m not saying it’s a good fit for all forms of tinkering.
Tinkering means different things to different people! Want to tinker with your hardware, as bare metal as possible? Or extract every inch of performance out of your CPU? Zig is great for that.
And not only that, if you're doing something in Python, somebody has done it before. Maybe not this exact thing, but something close enough to it. LLMs know it, Stackoverflow knows it, whatever esoteric protocol or file format you're trying to interact with, somebody wrote a library for it in the Python 2 days and has ironed out all the bugs since.
There's no other language quite like Python in this regard. Typescript is a close second, but the lack of metaprogramming facilities, no access to the type annotations at runtime, and the lack of operator overloading make some things needlessly complicated and uglier than they have any right to be.
I like that you have more freedom. You can play around with some idea but once you want to do something "serious" you can break into it directly. I start simple but sometimes blip into some performance obsession and I find Zig allows that.
The only language I've historically been able to claim to know without feeling like I'm straight up lying has been Python, and having got past my first maybe 1000 lines of Zig I can say pretty confidently that whatever magic makes Python feel comfortable to write, Zig has too.
It requires more of you in some ways, notably that you have to understand the basics of memory management and the behaviour of the stack, but so far I've found the affordances that the language provides for handling this stuff feel very intuitive.
The only sharp edges I've felt so far have been the sometimes hard to guess locations of things in the standard library, and the permenant anxiety that arises from knowing I'm going to be a few more versions behind the current release with every month that passes.
It's true that Zig is very readable. I haven't yet seriouly studied or written much of it, but browsing through codebases of popular Zig projects, a lot of it just makes sense intuitively. In that way it has a Python-like friendliness of syntax.
I enjoy the community and culture around Zig too. The other day I found a forum thread where people were sharing what they're currently building, and there were so many fun projects from small hobbyist things to large ambitious ones. For the latter, the main concern is the stability of the language, but the good thing is that everything is out in the open, everyone knows Zig hasn't reached version 1 status - but I can see concrete steps are being made to find a good solid interface, including this I/O stuff in 0.16. As someone casually learning the language, I find it refreshing to have insight into the development process.
I once had to write software that would go through whole bunch of PHP code (more than 5000 files), parse / discover certain patterns and write report with proposed fixes or same but with the fixes applied.
For whatever reasons I had to do it in Python. It was total nightmare to debug as the execution speed in debug mode was insanely slow.
I could've written it in C++ in exactly the same time and not to have any of the performance problems.
I won't call it "opinionated about how to use the language correctly."
Space is valid and it compile, Tab don't --- that's it.
When one say "opinionated about how to use the language correctly", I would think JavaScript with or without end of statement semicolon and being yell at even when your program works.
I have a lot of respect for Andrew, and I really enjoy Zig, but God that interview was awful. Andrews answers were fine, but the whole thing felt very sycophantic.
There is an idea I've been kicking around for a long time, which I'll just call dual programming. The idea is to develop a stack that consists of just two programming languages, 1 higher level language, and one lower level language. You are supposed to do as much programming as you can in the high level language, and only drop into the low level language as needed. The problem is that unless you already know a low level programming language really well, you'll most likely have to re familiarize yourself with the language before doing the low level stuff.
This makes Cpp and Rust harder to use then say C, so C becomes the default for me. But C is not without its issues of which we are aware. But Zig feels like it could fill that sweet spot really well, being simple enough that it's easier to pick up after a long break, but still coming with a lot of modern tooling that makes programming easier.
> You are supposed to do as much programming as you can in the high level language, and only drop into the low level language as needed.
I think that's a neat idea, but in the reverse: do as much as you can in the lower level language, and only go up to the high level language when the convenience is worth the cost.
Roc allows this: every program has a platform written in a low-level language, and then the Roc program uses the API that the platform exposes.
The OG of these is probably C and Assembly. C and (Emacs) Lisp is well known. Arguably, it's the entire reason we have Python. But if you want to pair Zig against something, I would look at Lua.
My kingdom for Zig to have an official mechanism to emit the Linux library stubs.
Zig’s ability to crosscompile and target arbitrary versions of glibc is PURE MAGIC. I leverage this magic in an unrelated C++ build system. But I have to hack around to get those library stubs from Zig. Would love it to be an official output.
In my experience, this (for now) is mostly aspirational. It's obviously a major goal, and there are clear milestones outlined on how to achieve it, but in practice the initial compile of an empty project or the excruciating pause when you `direnv allow` and ZLS needs to be (re)built are not what I'd describe as "terrific".
And running `zig test file.zig -OReleaseSafe` takes a couple seconds on my computer. It also keeps taking the same amount of time every time I do it when I modify that file. Using 0.16 (or master) version so my toolchain isn't old and I'm on linux.
Zig is super nice to use as a language but the compiler/stdlib isn't developed conservatively enough imo.
You may not run into an issue like this when starting out with hello world but you will want to run optimized binaries for fuzz testing or benchmarking. And then it becomes super annoying considering you might be compiling a relatively small amount of code.
Just for comparison, imo Zig is a much better language than these other languages, but if you did something like this in Rust/C++/C etc. this kind of issues basically doesn't ever happen. Assuming clang/gcc/ninja etc. usage for C/C++.
I am able to use Ninja/Python/clang for configuring/building (-O2 or -O3)/testing ~10k loc C++ project in 200ms on the same computer for example.
> And running `zig test file.zig -OReleaseSafe` takes a couple seconds on my computer.
What kind of computer are you on? I just ran that test (latest master build, first run):
~ % time zig test file.zig -OReleaseSafe
file.zig:1:17: error: expected type expression, found '{'
if (2 * 2 != 5) { @panic("fail"); }
^
zig test file.zig -OReleaseSafe 0.03s user 0.44s system 505% cpu 0.094 total
Granted I'm on an M4 Mac but I wouldn't expect another system to be 20x slower.
Also another point. I have some zig projects from couple of months back and they all have build.zig/build.zig.zon. I tried to copy that to the new dummy project I did and of course the API changed and that is broken now (just 15 lines of build.zig code).
This kind of thing just feels unacceptable considering I don't really see ANY improvement on the issues I had from back then.
Also had a similar baffling experience when I last tried to come back to writing Zig. The std.time.Instant or similar API that also exists in rust and most other languages was move to the new Io interface and they also completely removed that std.time.Instant code.
Overall it feels like people developing the tool don't respect the people using the tool. C++ or even Rust are much less enjoyable languages to write compared to Zig so it is really sad that it is not possible to actually use Zig for me.
Pascal has a lot of influence on this, but Go as well! My PL friends often talk about Go's benefits and flaws when thinking about advancing other their own projects or improving the mainstream languages they work on.
Go changed something, not sure if 20 or 21, where it will download the Go compiler of all your third-party which don’t match yours. It slows things down.
There is no ETA on 1.0, but breakage has followed the pattern of it not really being hard to upgrade to a newer version, as it is very well documented on the version release notes.
writergate was not smooth, a lot of things that moved over to writer (Writer.Allocating for instance) had no documentation and I had to go read the zig source code to figure it out. the docs were just "instead of That use This"
Yep. He mentioned recently in his JetBrains interview he wants Zig to be a language for the next 50 years. Rushing 1.0 for the sake of signaling to the wider industry today would be actively harmful to that goal.
Too bad it will not be adopted for anything serious in the next 50 years. There is no reasonable value proposition from a business standpoint for picking zig over rust. It is already the reality in much of the tech industry that Rust is filling the space previously occupied by C++. The fact that there now exists a safe low level language is legitimately a paradigm shift. It doesn't matter how many shiny cool things zig adds, being unsafe means it a technology stuck in the past.
I think bun is moving to rust because Anthropic owns it and the devs there like rust. So why would they invest in another implementation? Sad to see a good zig example go, but as soon as Anthropic bought it I wrote the project off.
I am not aure either, but bun wasn't using normal zig and there was drama about upstreaming. Combine that with anthropics desire to show they can help rewrite everything in rust and that probably accounts for some of it.
Bun has de-facto refused to use incremental compilation in Zig for ages. It got to the point where Jarred somehow seems to have forgotten that the feature exists.
In any case Bun has already committed to the Rust slop switch, so it doesn't matter anymore.
bun seems to be committed to slop rust already. so, with their ethic, maybe we should just disassociate them from zig and let them go realize their slop dreams?
zig is on its way to improving compilation times in its own pace and does so for the benefit of the project and everyone involved, so what is left to care for about bun by anthropic’s past?
I bet they'll ultimately reverse course on this, or the there will be a bun / zig fork becomes the de facto bun. Despite what the influencers say, I'm convinced you cannot vibe code a conversion this big. It will need a ton of human intervention. And for brand narrative reasons, Anthropic won't commit to such a path.
It depends on how thorough the test infrastructure is I think. Something like curl with its immaculate tests could probably get autonomously ported if you threw infinite tokens at it because you have deterministically defined what finished looks like. But I think you are likely right in this case.
> bun seems to be committed to slop rust already. so, with their ethic, maybe we should just disassociate them from zig and let them go realize their slop dreams?
Closing your eyes and pretending a problem does not exist is the a good solution. The fact of the matter is one of the biggest projects that used Zig thought that the devX was so bad that they opted to rewrite their entire 1M LOC project into a different language. This is a nightmare scenario for most companies, and will motivate similar sized companies/project to pick another language that will not require this than to risk using Zig. Also, Zig’s flippant attitude about Bun’s request (among other viewpoints) only further adds to why bigger projects would want to stay away from Zig.
> The fact of the matter is one of the biggest projects that used Zig thought that the devX was so bad that they opted to rewrite their entire 1M LOC project into a different language.
That is not the fact of matter. The fact is it got bought by Anthropic. And in larger scheme of things Bun is one example Claude capabilities of translation. And even if doesn't work, it just a part of Claude desktop stack so still have millions of installs.
Not really, if it doesn’t work then it will hurt their flagship desktop app’s stability, which would negatively affect their placing in an already cutthroat AI arms. Claude Code is the few business asset that Claude has the least moat compared to other providers( even open source). They can’t afford to be sloppy and use a buggy JS engine.
> The fact of the matter is one of the biggest projects that used Zig thought that the devX was so bad
It's unlikely to be just a devex issue. The fact of the matter is that a memory unsafe language is an extremely tough sell today, and companies that have a security team at all have likely already made or are planning on making policies like https://chromium.googlesource.com/chromium/src/+/master/docs...
There's a reason "rewrite it in Rust" was a meme long before LLM coding tools or this Bun drama. With AI accelerated fuzzing techniques and similar, memory safety is rapidly going to become a basic requirement of anything run in a production environment.
I don't remember where it was said first, but I think the problem was not "AI drama" or that zig doesn't have "a good solution". It was more a mismatch between Bun's & Zig's goals. Bun wants to move fast & break things, even more now after getting acquired, but Zig punishes that. Zig requires you to handle everything carefully, there's no GC or big runtime to let you "break things", zig will let you just segfault.
Companies like TigerBeetle can and will benefit from zig's model.
But this goes to my second point; it seems like Zig wasn’t open to any compromise about the solution that Bun submitted and one they built in house. Is it the Zig culture to reject a pull request like that wholesale? It’s really odd for them to have such a flippant attitude and not to even try offer ways that they could use the pull request or things that they need to tweak to make it more inline with what they want. Companies want to use languages that have a understanding committee, and are willing to work together to create solutions, not just say “No, this isn’t what we want, and we are building a similar system anyway so don’t even bother to try again”. It just looks unprofessional.
A large, complex, unasked for PR is pretty likely pointless to throw at any serious project. (Well, it's pointless if your goal is to merge something.)
Working together is a two-way process. To land a big change, the bun people probably needed to have been working/coordinating with the zig people throughout. E.g., zig outright cannot accept PRs that break the language in unplanned ways and any conflicts with the roadmap would need to be resolved.
I would assume the bun people know all this. That makes it more of a publicity stunt than a serious attempt to contribute to zig, and we should probably all treat it that way.
Of course, and it is expected that large pull requests/RFCs are iterated on. I will not believe Bun seriously asked for a pull request to be merged with absolutely no expectation of back and forth discussion. But this isn’t what happened. The whole reason everyone thought it was rejected by Zig because Bun used LLM to generate it was because they responded in a way that someone would if they didn’t want a certain pull request accepted under any circumstances. Which is my point; it I just insane that their largest project submitted a pull request, and they just rejected it with prejudice, gave some statement saying the real and potentially fixable reasons why, then turn around and say we don’t want your help, we are doing this in house.
Compromising on project goals just because someone with somewhat different goals made a pull request doesn’t exactly scream responsible and professional to me. The way I understand it, many people appreciate Zig because it’s very consistent and restrained about the kinds of problems it’s trying to solve and how, so being very careful with accepting complex, externally developed solutions seems perfectly in character for the language.
I’m not sure how well the Zig developers have handled their communication, so perhaps there really was room for improvement there.
I believe if the work you do fits well with Node & TS, you have no reason to use zig (other than for learning or curiosity). Like, if you don't need every drop of performance, memory layout & control, there's more downsides to using zig. Idk, cruds or "enterprise" stuff or websites don't benefit from zig.
You can't run Node on embedded systems, because there isn't enough memory.
A compiled zig program can be only several kilobytes with no depedenencies.
Array access programmed in low-level languages can be optimized with SIMD and parallelization, which will be orders of magnitude faster than the same thing on Javascript. Text processing, image manipulation, video processing, hashing, etc.
There is like infinite reasons to not use Javascript.
Zig has so many compelling features, and I'd even be willing to give up Rust's near-perfect memory safety in some cases. But the one thing that really put me off is string handling. It's just so super tedious. I like being able to finely manage individual string memory allocations, but I really don't want to have to do it all the time. RAII is great; I wish they'd use some light (optional) RAII for strings and containers etc.
It is. I definitely agree that strings in Zig can be tedious, but the upside is that if you need it, you can build a string library that does everything you want it to do, in the way you want.
For comparison, while Rust offers a very rich string library, it's also very strict about what you can/cannot do with strings, so if your use case falls outside of that you're out of luck. With Zig, you can pretty easily roll your own and make it do what you want. (and when Zig is post 1.0, I imagine there will be some very nice pre-made string libraries by the community etc.)
Tbh I don't know enough Zig to answer that. Can you give an example? E.g. some non-performance-sensitive function that returns a string? In Rust and C++ you can treat the string exactly the same as you would an integer and it's super easy.
In C you have pain. Does the caller allocate a buffer? How does it know how big to make it? Do you have to have separate calls to calculate the required length? Etc. Can Zig work like Rust/C++ and not like C? My impression is that it can't.
An arena allocator lets you treat a series of allocations as a single block. In cases where you find yourself needing to micromanage a bunch of small memory allocations you can simply ignore freeing them individually and free the whole arena when you are done.
Because it isn't memory safe. I honestly think it's beyond the point of "irresponsible" and well into "negligence" that we're still developing unsafe technologies - people are being harmed by this choice. It's one thing when you have to target specific platforms and maybe Rust wasn't an option or whatever, but the reasons to choose unsafe languages at this point are vanishingly small.
Zig is very cool, I love many aspects of it. I'll never touch it, I'll always advocate against it tbh. I'd probably advocate that software written in languages like Zig be flagged for FEDRAMP and other environments since devs seem to not care unless they're legally barred from making these sorts of choices.
I don't think Rust users are relevant here. It primarily comes down to personal preferences, and since Zig and Rust are so different, some will be drawn to Rust and others to Zig. If you really like a language and it suits your needs, be it Rust or any other, there's no need to look to switch. I think that the audience Zig is aimed at is low-level programmers who haven't taken a liking to Rust, which is the majority of them. Rust isn't very popular among experienced low-level programmers (certainly for a language that old), and I guess Zig is hoping to be more to their liking.
For example, I find Rust to be far too similar to C++, and it shares most of the problems I have with C++ only with much lower adoption. I'm not saying I'm ready to make the switch, but at least Zig offers a different approach that's intriguing to me.
Try it if you want full control over every memory and IO operation and "drop". If you hit "goto-definition", you eventually get to see the OS switch statements and syscalls. There's not much magic.
Do not try it if you are scared of memory management and memory leaks.
Not working within the bounds of lifetimes, and more ecosystem that doesn't live in the world of lifetimes, gives Zig some of the wonderful dev ergonomics of Rust while making it easier to prototype.
For small, short game dev, or even smaller embedded projects, this ends up being a wonderful way to live as often times you're trying to eke out performance in ways that would require breaking out of whatever type abstractions or using unsafe.
For long-lived systems, for systems that need to have lots of people with various skill levels work on them, for a mature ecosystem, for a language/standard library with stability... You probably don't want to pick Zig right now. Some of these points will change over time with Zig becoming more mature, some won't. Zig will always be super cool to build things in.
As far as most low-level programmers not liking Rust like some other commenters say, lol, lmao even.
There are different licenses that used to be referred to as "MIT", and explicitly stating "Expat" tells you which one they're referring to (in this case, the "standard" one). This is largely unnecessary, as nearly all mentions of the MIT license refer to this one.
Carpentry would have been ideal career. Building real things, artisanal or not, and nobody insisting yet that the chest of drawers you're building include AI
If you haven't tried Zig since 0.16.0 was released, I highly recommend having a look. The release notes for this release were huge!!
https://ziglang.org/download/0.16.0/release-notes.html
I had some trouble understanding how the async/await mechanism works:
My assumption is that calling io.async using an event loop implementation of IO, it will internally start a "task" (or whatever it should be called) and that the future is a handle to it. So far so good.The part that I don't understand is what happens when you call future.await(io). Will the IO implementation somehow suspend the current function and resume once the future is resolved? If so, does that mean that every function in zig is a stackless coroutine?
No and yes.
If you're using Io.Threaded, then the concurrency model is multithreading and calling Future.await will block your thread on a OS futex.
If you're using Io.Evented, then the concurrency model is green threads / fibers and calling Future.await will suspend the current green thread by yielding (swapping CPU state with another fiber).
Zig currently does not support stackless coroutines so today you can't have that, but we used to have them (pre self-hosted compiler), and there's an accepted proposal to bring them back, in which case any function that calls await, or that otherwise has a suspension point, would have to be transformed into a stackless coroutine by the compiler, yes. The plan is for that to happen transparently without requiring an `async` annotation in the function signature, like we already did in the past.
This is an old post of mine that explains how that worked at a high level: https://kristoff.it/blog/zig-colorblind-async-await/
the upcoming releases are expected to provide a solution to this “dispatch is comptime-known, but still dynamic” problem, and drop the loses in efficiency.
That is, I think the point was DevX not io performance.
For me it is now the go-to "tinker in my garage" language.
It doesnt let you have unused variables and theres no multiline comment support. These are fairly significant productivity issues for me
Ugh. This is something I hate about Go. I would be happy to have unused variables generate warnings, but as errors, they turn the toolchain into an adversary.
It's common for me to temporarily comment out a variable's use when developing new code, as I experiment with ideas. It's even more common when working in unfamiliar code, such as tracking down a bug or incrementally adding a new feature. It's an important part of my exploration process.
When I hit Compile at that point, I expect the compiler to build the work-in-progress exactly as it is in that moment. Executing the output allows me to spot check the snapshot's behavior against my expectations and mental model. The compile step also assures me that no syntax errors have crept in while I was focused on the logic flow or general shape of the code.
When a compiler refuses to do its job, and instead barfs up spurious errors complaining about unused variables, it brings my workflow to a screeching halt. In order to make progress, I am forced to abruptly leave my current context to visit all the different places where those variables are introduced, edit them, try again, discover that those forced edits have left more variables unused, and repeat the process until the combative compiler shuts up and does what I told it to do in the first place. By the time I'm allowed to return to what I was doing, my train of thought has been derailed, the bits of logic that I had been juggling have fallen to the ground, and my focus destroyed. And then, once I have recovered my original thoughts and seen the output of my snapshot build, I have to go back and revert all those forced edits before I can resume my work.
What an aggravating, disruptive, and completely unnecessary waste of my time and attention.
I hope Andrew has the good sense to let errors of this kind be silenced or demoted to warnings, perhaps with a compiler flag or debug build mode.
If they wanted the release build to be an error I wouldn't care. Having the current solution be "have the editor automatically change code to include or remove the underscore" is so wrong to me. Just invented a problem that needs tooling to modify source code to fix.
Multiline comments are less important, but its still convenient for commenting out large chunks of code. IDEs make this a bit easier when you can press e.g. Ctrl+/ to comment out the selected lines with //, but it doesn't work in all cases.
The friction stops zig from being fun imo. A shame because I really like comptime.
My go-to "tinker in my garage" language is Python - lightweight syntax that stays out of your face, batteries included, packages for everything that's not included. What's Zig's edge?
As for the language itself, it's going to be more verbose than your Python code. Cons: you'll have to spell out a lot of things that you thought were obvious assumptions. Pros: you will be able to look at a page of code and know with a great degree of certainty that there are no hidden gotchas. No monkey patching, no __init__. Basically, it just does what it says on the tin.
And finally, about the std lib and batteries: there's HTTP(S), compression algorithms, hash algorithms, RNG, I/O, the basic data structures you'd expect, JSON. Third-party libraries, if you choose not to vendor, are handled by including the repository url in a file (also automated by a CLI command), and then adding it to the build script (not automated). The `zig` command handles fetching and ensuring sanity, but otherwise assume a bit of elbow grease will need to be involved.
Batteries included, automatic memory management without a conventional GC and metaprogramming - is a really cool combination.
[0] - https://nim-lang.org/
Wish I had the time and skill to actually contribute to the LSP, if you have ever used Nim it's a seriously underrated language.
It's making fast progress and will provide the basis for a proper LSP! Nimony already supports incremental compilation and parallel which are key pieces for good fast LSP.
The nice thing is that all these languages feature easy C interop so you can use a C FFI as the interface between them if you want to experiment with, for example, writing a module in Nim
For the rare exceptions, I make a C lib and call into it to get my numbers crunched. I get that Zig is a viable replacement for C there. But I don't see it replacing Python.
The problem is that most people using Python don't have enough expertise in C to do the same.
It also kinda destroys the argument that Python is good if your solution for performance is to use a different language alongside it.
But... the LSPs I've tried (and I've tried a bunch!) are all atrocious: false positives and false negatives galore. Perhaps I'm spoiled by LSPs from languages with better type systems. Our code is strewn with (to me) mysterious comments such as `# NOQA 1234` which my colleague uses to make his Python tooling work with the codebase. I'm used to languages like Elm or Gleam in which a LSP error means there is an actual problem with your code, and a lack of a LSP error means the code will compile and run.
Last little project I remember is writing a solver for a puzzle game my friend published. Python just doesn't work at all for such tasks.
I think you are wrong about speed of those libraries as well. In my experience naive code designed for a specific task beats highly sophisticated general code and it doesn't take a rocket scientist to get huge speed-ups over some well established fast library.
There's not much magic in Zig. Keep hitting goto-definition and you can eventually see the OS switch statements and syscalls.
Zig is a return to “no magical effects,” except with reasonable safety
These reports are smoking crack. Rust scales gloriously well into large codebases, and it especially shines when it comes to making major refactorings. Please don't bother speaking about things that you don't understand.
Rudeness may be acceptable elsewhere. Not here.
I like Python as a tool language, and I am very impressed by projects like Micropython, but you always eventually run into a wall. I.e. you are never going to write a compute shader in python, but I assume someone is going to try.
I think the programmer should meet the hardware in the middle, and Python has a few too many layers of indirection to do this well.
Yes, in general, but also there are cases when you realize you can, idk, parse a CSV file in 0.2 seconds instead of 200 seconds. That kind of improvement unlocks a new level of tinkering.
When I want to tinker, I just want my logic to work, first of all. In 9 cases out of 10 that means going for high level. Even if the resulting code works with low level things like binary structures.
C++ adds more high-level conveniences without actually removing the footguns and undefined behavior (much C code compiles in a C++ compiler).
Zig tries to keep the low-level C philosophy but have things more well factored and well defined. The result is you _can_ tinker in high-level code, yet "drop down" into low-level code as you desire.
(Compared to rust, you get fewer compiler-enforced guarantees, but unlike C the language isn't trying to make high-level code adversarial).
I haven't really used modern C, not sure if it's evolved as much as modern C++, which I feel is a joy to use, and a lot safer. But then I've been writing C++ for decades.
I feel like C evolved from basically syntax sugar for assembly, so that's where all the footguns come from, rather than being actually adversarial.
For some reason this always brings to mind that moment in Red Dwarf where Kryten, devoid of his behavioural chip, deems it appropriate to serve roast human to his crewmates. "If you eat chicken, obviously you'd eat your own species as well, otherwise you'd just be picking on the chickens!"
It's arguably the closest modern language (with a sizeable community) to the Wirthian languages.
http://odin-lang.org/
There is Swift as well, although quite far from Wirthian compile times.
I've been places, from embedded bare metal to ML AI, and that "embedded bare metal" end is the one place I don't use Python directly in. Embedded bare metal is just ruled by C forever.
Bit of a shame, because C is kind of bad at its job, but nothing else has the "compatible with everything" badge of honor.
The tooling around embedded devices though? Python.
If you only ever think of tinkering for the purpose of execution speed ninjutsu, isn't it your definition of tinkering that's far too narrow?
I personally think the optimization challenge is fun. I like digging in to low level stuff, reviewing the assembly dumps and processor pipeline architectures. I fail or give up most of the time, but I enjoy learning in the process.
I’m just trying to show how Zig fits my tinkering well, since you said you can’t see how Zig would ever be a good fit for tinkering. I’m not saying it’s a good fit for all forms of tinkering.
what the heck has convinced you that logic is somehow flawed in a new low-level language? LOLLL
Some people put a generator on a tesla cybertruck and call that garage tinkering.
Some people make a go-cart out of a lawnmower and call that garage tinkering.
The first is the "batteries included Python" tinkering, the second is the "low level Zig" tinkering.
There's no other language quite like Python in this regard. Typescript is a close second, but the lack of metaprogramming facilities, no access to the type annotations at runtime, and the lack of operator overloading make some things needlessly complicated and uglier than they have any right to be.
It requires more of you in some ways, notably that you have to understand the basics of memory management and the behaviour of the stack, but so far I've found the affordances that the language provides for handling this stuff feel very intuitive.
The only sharp edges I've felt so far have been the sometimes hard to guess locations of things in the standard library, and the permenant anxiety that arises from knowing I'm going to be a few more versions behind the current release with every month that passes.
I enjoy the community and culture around Zig too. The other day I found a forum thread where people were sharing what they're currently building, and there were so many fun projects from small hobbyist things to large ambitious ones. For the latter, the main concern is the stability of the language, but the good thing is that everything is out in the open, everyone knows Zig hasn't reached version 1 status - but I can see concrete steps are being made to find a good solid interface, including this I/O stuff in 0.16. As someone casually learning the language, I find it refreshing to have insight into the development process.
For whatever reasons I had to do it in Python. It was total nightmare to debug as the execution speed in debug mode was insanely slow.
I could've written it in C++ in exactly the same time and not to have any of the performance problems.
Space is valid and it compile, Tab don't --- that's it.
When one say "opinionated about how to use the language correctly", I would think JavaScript with or without end of statement semicolon and being yell at even when your program works.
This makes Cpp and Rust harder to use then say C, so C becomes the default for me. But C is not without its issues of which we are aware. But Zig feels like it could fill that sweet spot really well, being simple enough that it's easier to pick up after a long break, but still coming with a lot of modern tooling that makes programming easier.
I think that's a neat idea, but in the reverse: do as much as you can in the lower level language, and only go up to the high level language when the convenience is worth the cost.
Roc allows this: every program has a platform written in a low-level language, and then the Roc program uses the API that the platform exposes.
https://www.roc-lang.org/
Then how you want to balance high vs low is of course up to you :^)
https://github.com/E-xyza/zigler
Zig’s ability to crosscompile and target arbitrary versions of glibc is PURE MAGIC. I leverage this magic in an unrelated C++ build system. But I have to hack around to get those library stubs from Zig. Would love it to be an official output.
This is amazing. Didn't 0.16 take >1 year?
I was not expecting such a fast 0.17 release, but am very pleased to find this out today.
In my experience, this (for now) is mostly aspirational. It's obviously a major goal, and there are clear milestones outlined on how to achieve it, but in practice the initial compile of an empty project or the excruciating pause when you `direnv allow` and ZLS needs to be (re)built are not what I'd describe as "terrific".
It sounds like you are a strong candidate to try out the new improvements mentioned in this devlog and see what benefits you can get for yourself.
if (2 * 2 != 5) { @panic("fail"); }
And running `zig test file.zig -OReleaseSafe` takes a couple seconds on my computer. It also keeps taking the same amount of time every time I do it when I modify that file. Using 0.16 (or master) version so my toolchain isn't old and I'm on linux.
Zig is super nice to use as a language but the compiler/stdlib isn't developed conservatively enough imo.
You may not run into an issue like this when starting out with hello world but you will want to run optimized binaries for fuzz testing or benchmarking. And then it becomes super annoying considering you might be compiling a relatively small amount of code.
Just for comparison, imo Zig is a much better language than these other languages, but if you did something like this in Rust/C++/C etc. this kind of issues basically doesn't ever happen. Assuming clang/gcc/ninja etc. usage for C/C++.
I am able to use Ninja/Python/clang for configuring/building (-O2 or -O3)/testing ~10k loc C++ project in 200ms on the same computer for example.
> if (2 * 2 != 5) { @panic("fail"); }
> And running `zig test file.zig -OReleaseSafe` takes a couple seconds on my computer.
What kind of computer are you on? I just ran that test (latest master build, first run):
Granted I'm on an M4 Mac but I wouldn't expect another system to be 20x slower.This kind of thing just feels unacceptable considering I don't really see ANY improvement on the issues I had from back then.
Also had a similar baffling experience when I last tried to come back to writing Zig. The std.time.Instant or similar API that also exists in rust and most other languages was move to the new Io interface and they also completely removed that std.time.Instant code.
Overall it feels like people developing the tool don't respect the people using the tool. C++ or even Rust are much less enjoyable languages to write compared to Zig so it is really sad that it is not possible to actually use Zig for me.
It's different and I like it. You get one shot at it and may just as well get it right in as many areas as possible.
https://ziggit.dev/t/bun-s-zig-fork-got-4x-faster-compilatio...
That said, I hope that Zig posts won't be plagued by "but the bun thing" like this in the near future.
In any case Bun has already committed to the Rust slop switch, so it doesn't matter anymore.
zig is on its way to improving compilation times in its own pace and does so for the benefit of the project and everyone involved, so what is left to care for about bun by anthropic’s past?
Closing your eyes and pretending a problem does not exist is the a good solution. The fact of the matter is one of the biggest projects that used Zig thought that the devX was so bad that they opted to rewrite their entire 1M LOC project into a different language. This is a nightmare scenario for most companies, and will motivate similar sized companies/project to pick another language that will not require this than to risk using Zig. Also, Zig’s flippant attitude about Bun’s request (among other viewpoints) only further adds to why bigger projects would want to stay away from Zig.
That is not the fact of matter. The fact is it got bought by Anthropic. And in larger scheme of things Bun is one example Claude capabilities of translation. And even if doesn't work, it just a part of Claude desktop stack so still have millions of installs.
It's unlikely to be just a devex issue. The fact of the matter is that a memory unsafe language is an extremely tough sell today, and companies that have a security team at all have likely already made or are planning on making policies like https://chromium.googlesource.com/chromium/src/+/master/docs...
There's a reason "rewrite it in Rust" was a meme long before LLM coding tools or this Bun drama. With AI accelerated fuzzing techniques and similar, memory safety is rapidly going to become a basic requirement of anything run in a production environment.
Companies like TigerBeetle can and will benefit from zig's model.
Working together is a two-way process. To land a big change, the bun people probably needed to have been working/coordinating with the zig people throughout. E.g., zig outright cannot accept PRs that break the language in unplanned ways and any conflicts with the roadmap would need to be resolved.
I would assume the bun people know all this. That makes it more of a publicity stunt than a serious attempt to contribute to zig, and we should probably all treat it that way.
I’m not sure how well the Zig developers have handled their communication, so perhaps there really was room for improvement there.
You can't run Node on embedded systems, because there isn't enough memory.
A compiled zig program can be only several kilobytes with no depedenencies.
Array access programmed in low-level languages can be optimized with SIMD and parallelization, which will be orders of magnitude faster than the same thing on Javascript. Text processing, image manipulation, video processing, hashing, etc.
There is like infinite reasons to not use Javascript.
Is it not possible to build a wrapper that does this? It seems like it should be.
For comparison, while Rust offers a very rich string library, it's also very strict about what you can/cannot do with strings, so if your use case falls outside of that you're out of luck. With Zig, you can pretty easily roll your own and make it do what you want. (and when Zig is post 1.0, I imagine there will be some very nice pre-made string libraries by the community etc.)
In C you have pain. Does the caller allocate a buffer? How does it know how big to make it? Do you have to have separate calls to calculate the required length? Etc. Can Zig work like Rust/C++ and not like C? My impression is that it can't.
Because it isn't memory safe. I honestly think it's beyond the point of "irresponsible" and well into "negligence" that we're still developing unsafe technologies - people are being harmed by this choice. It's one thing when you have to target specific platforms and maybe Rust wasn't an option or whatever, but the reasons to choose unsafe languages at this point are vanishingly small.
Zig is very cool, I love many aspects of it. I'll never touch it, I'll always advocate against it tbh. I'd probably advocate that software written in languages like Zig be flagged for FEDRAMP and other environments since devs seem to not care unless they're legally barred from making these sorts of choices.
For example, I find Rust to be far too similar to C++, and it shares most of the problems I have with C++ only with much lower adoption. I'm not saying I'm ready to make the switch, but at least Zig offers a different approach that's intriguing to me.
Do not try it if you are scared of memory management and memory leaks.
For small, short game dev, or even smaller embedded projects, this ends up being a wonderful way to live as often times you're trying to eke out performance in ways that would require breaking out of whatever type abstractions or using unsafe.
For long-lived systems, for systems that need to have lots of people with various skill levels work on them, for a mature ecosystem, for a language/standard library with stability... You probably don't want to pick Zig right now. Some of these points will change over time with Zig becoming more mature, some won't. Zig will always be super cool to build things in.
As far as most low-level programmers not liking Rust like some other commenters say, lol, lmao even.
The "Expat" here is the MIT license variant. It is referring to the Expat XML parsing library that first used this license.
Usually when projects these days use an MIT license this is the version they use.
I'm not even thinking of AI, but Rust. I guess I'm just uninterested in a "modern C".