Rune: A native GPU-rendered Rust UI framework for macOS, Windows, Linux and web

21 hours ago (github.com)

If you're interested in a GPU-rendered Rust UI framework, then maybe skip this vibe coded project, and check out some of following established projects:

  Rust-native GUI frameworks (by crates.io downloads):

   1. egui (30.3M total / 9.2M last 90 days)
      https://crates.io/crates/egui

   2. Iced (3.2M / 770k)
      https://crates.io/crates/iced

   3. Slint (2.4M / 955k)
      https://crates.io/crates/slint

   4. GPUI (447k / 255k)
      https://crates.io/crates/gpui

   5. Dioxus Native (181k / 26k)
      https://crates.io/crates/dioxus-native

   6. Freya (49k / 12k)
      https://crates.io/crates/freya

   7. Floem (45k / 15k)
      https://crates.io/crates/floem

   8. Vizia (7k / 700)
      https://crates.io/crates/vizia

List is hand-picked list, ordered by crates.io downloads. I had an LLM fetch the download counts and links. Webview based UI like Tauri and Dioxus Desktop are excluded. As are bindings to native toolkits and GTK.

  • IMO, the top GUI framework crates for Rust are windows or native-windows-gui, objc2 or icrate for MacOS and gtk4-rs for Linux only. Actually for MacOS / iOS I'd use uniffi to embed the rust core in a SwiftUI app.

    In 2026 IMO it's much better to use an LLM to keep 3 separate native front ends in sync than it is to try and use any sort of cross platform UI.

    • Could you please explain why? For example: Is it colors? A je-ne-sais-quoi? Widget rounding size and fonts? Performance reasons? Keyboard shortcuts? Do you really find it's easier to maintain 3 separate frontends using an LLM than using EGUI, GPUI, QT etc?

      I have seen this suggestion several times recently regarding GUI framework threads on HN in the past week (There has been a surge!), but they are always described in the way you did: With no explanation of why. Just an assertion that native UI kits (of which you need a separate one for each OS family) are superior; cross-platform kids are an "inferior experience" etc. I have asked at 3 times and received no answer. I say this as someone who uses both Windows and Linux regularly, and find they are functionally equivalent once you have an application launched. There are ABI differences, driver differences, file system differences, etc which need to be smoothed over with feature gates for certain application functionality, if you're using certain functionality.

      I want my applications to have the required functionality, run fast, and have a good UI. I don't care if the widgets look the same as on my other applications or the ones built in to the OS; this isn't even a thing because there is so little standardization broadly. Maybe on Macs it's standardized and cross-platform kits look out of place?

      The proposed approach of "Use LLMs to vibe-code a system of 3 native kits" has cons to weigh. Or making your program Windows only or w/e for a look-and-feel reason or whatever it is has cons too. IMO all our OSes are so similar, PC software should almost all be cross-platform. Exceptions are mostly drivers and driver-adjacent code.

      1 reply →

    • Keeping 3 separate native front ends in sync with custom visual components means you end up building a cross-platform UI. The only apps you can build without custom components are trivial ones.

      4 replies →

    • An advantage of this approach is that everyone's screen readers and other accessibility tools actually work with your app.

  • https://crates.io/crates/dioxus-native was released 3 months ago and does not have a link to GitHub, I do not think it can be considered as established project yet.

    • (I am the maintainer of dioxus native, and also posted the comment above)

      So:

      - The initial version was released over a year ago (3 month is the most recent patch release of the stable version).

      - It is part of the Dioxus project (https://github.com/dioxuslabs/dioxus) which has been going since 2021 (but the other renderers are web/webview based).

      - The native renderer (https://github.com/dioxuslabs/blitz) has been under development since December 2024 (building a whole new web engine is just a big project).

      You're ultimately kind of right that it's not as established as 1-4 in the list. But I think it justifies it's place with the other frameworks lower down the list as one of the lesser-known frameworks that compete technically with those further up the list.

      4 replies →

  • Yeah, have you tried to do anything in egui? I tried today a ComboBox, but I wanted one with filter input box, "X" icon to clear it, and automatic focus.

    I've given up when the code reached 300 lines and was still buggy/not working.

    egui is not mature. I'd prefer declarative approach, data binding, and styling. Therefore will skip egui.

    • i've built pretty complex stuff in egui. any modern agent will one-shot that component, so i'd say it's more just a lack of familiarity with the library.

  • Slint is proprietary. Given that AI makes it so easy to spec out and build even entire GUI frameworks, why would you even go with proprietary anymore? And why doesn't the article showcase a full-fledged set of UI components?

    • I might be wrong, but I believe Slint has qt-style dual-licensing and provides AGPL version for GPL projects.

      I assume you make an open source project giving the critics about proprietary nature, so it shouldn't be a problem.

    • > AI makes it so easy to spec out and build even entire GUI frameworks

      When a vibe coded gui framework becomes so good that it simply cannot be ignored, I'll believe this can work. Until then, all I've seen is half-baked disposable slop that looks really good on paper.

  • > List is hand-picked list, ordered by crates.io downloads.

    O_o

    Just say it’s a hand picked list of ones you like and why.

    Do you like them? Have you used them?

    I found iced to be unreliable (couldn't reliably render basic widgets); slint overly relies on their DSL and honestly seemed to be moving away from rust; and GPUI felt sloppy. That was my personal “lets try rust gui” journey before I went; nope, guess we’re doing native ui and a shared rust core.

    This is just a random list of stuff; I can't tell if you think they're all good (I dont) or just copy pasted chatgpt output.

    For each one: why is it on the list? Do you like it? Why do you think, for example, slint, deserves to be on the list, when you dont even write the ui scripts in rust?

  • Luckily GPUI isn't vibe coded at all but a mature and well thought-out project.. /s

    • I tried using it and yeah, GPUI felt very sloppy. Something about that lack of documentation + having to install it from some subdirectory in a giant monorepo + Tailwind-based API...

      And the recommended component library for it (GPUI Kit) seems to have been 100% Clauded, down to the website and README.

      2 replies →

Sort of a digression, but it's the first time I've seen something like this:

    > We don't take pull requests. Have your agent open
    > an issue describing the bug or idea, and our agents
    > usually turn it around fast.

Pretty interesting approach, compared to receiving a zillion potentially sloppy PRs. Open source in the age of LLMs.. ("agent source"?)

  • I find this line pretty sad actually, what if someone wants to contribute code, written by hand? What if some beginner finds this project interesting and wants to invest own time into it?

    Or human is completely removed from the development whatsoever..

    • > I find this line pretty sad actually, what if someone wants to contribute code, written by hand? What if some beginner finds this project interesting and wants to invest own time into it?

      Then they would be better off contributing to a project that welcomes them.

    • While I sympathize I think we all know a majority of contributions would not be hand written. This is optimizing for the reality we're in.

      You could fork and reference it in the issue if you still wanted to contribute.

    • > what if someone wants to contribute code, written by hand?

      It's up to the maintainer. Sometimes it's just easier to listen to what's needed and do it the way you know and are efficient with than to review someone else's code.

      > What if some beginner finds this project interesting and wants to invest own time into it?

      There's nothing stopping them. They can even publish it in a fork.

    • Why would any beginner want to contribute or invest a large amount of time where he doesn't trust a maintainer or their processes?

    • Yep. There's other projects that have a "we want your ideas, but not your code" policy (like SQLite and Lua), but the "just tell your agent to tell our agent what to do" framing makes me depressed.

  • I did the same for a vibecoded project [0] but I would never do this for a human-written project. Simply put, if most contributions are similarly vibecoded and/or they will be reviewed/treated as such, then how is a PR/review from an unaffiliated agent any better than one managed by the project curator. Of course that human curation still needs to occur.

    This is a natural progression (only on these types of projects). We accepted contributions because it actually helped and they were difficult and time consuming. When that is no longer the case, contributions are a burden, the actual problem/idea is the real value, hence the request to open the issue.

    0 - https://github.com/cretz/vitaslop

  • Won’t this just lead to bloatware in the long run? Part of creating a product is knowing what to say no to. And I’ve found my customers’ ideas for how to improve my products aren’t always the best way to implement the feature they want (or it would create issues for other customers who use it differently).

  • I had a Nix issue. Agents fixed it in 5 min.

    Of course, one could conclude that another agents screwed up before, still was a good experience.

  • It sounds like a black hat penetration tester's nirvana. All you have to do is open the right issue to trick the model into installing the right security vulnerability or backdoor, or better yet, a series of small security vulnerabilities that can be chained to create a tailor-made exploit. It's practically a hacker's choose-your-own adventure.

    • I am not sure about that.

      Which gate is easier to maintain?

      1. Check issues for malicious intent

      2. Check PR for malicious intent.

      I think in PR requests it is easier to introduce purposeful bugs or obfuscated code than it is to hide them in issues.

      So I think gating on issues is easier and more secure.

    • I suspect they'd be manually filtering which issues/features their agents attempt to fix/implement. Otherwise you end up with all sorts of features that simply make no sense for the project.

      The approach is at least better than accepting slop PRs that could have backdoors injected into them.

  • My main concern with this would be that for a library in particular I need a stable API and behavior (Hyrum's law). I do not know to what extent a fully autonomous agentic approach can ensure that. Note: I don't see a problem with preferring issues over pull requests (many of which would be poorly coded slop), just fully automating the handling.

    Also a bit wild to assume that no person will just create an issue manually. This is not something I'd normally use an agent for.

> Every app can run headless, so an agent can render to PNG, dump the element tree and drive it with scripted input.

This is cool. I hope SwiftUI / UIKit borrow this idea for native mac apps.

  • You can do the same thing with swiftui. The surface you render to doesn't have to be visible at all. And the tree has nice introspection available.

  • Headless part is neat, but agents can already drive apps and take screenshots. As a side note, I have agent driving android tv using wireless adb and hdmi capture card + mpv rpc, its fun to watch.

How should I think about this, compared to GPUI (https://gpui.rs)? What are pros and cons?

  • Has GPUI development even picked up since the Zed team gave up on it? The GPUI website still links directly to the Zed repo's subfolder. I can't tell if there's even one coherent GPUI project any more

Does this have:

- Accessibility? E.g. Screen reader support?

- Alternative inputs? Full keyboard support?

- Full internationalization, including right-to-left and diacritics?

What happens when no GPU is available?

Just curious as this matters for it to be a serious library and not a proof of concept.

Looks interesting, especially the headless part. Been building various apps lately for ios/ipados/macos for personal use and I would love something like this that would be truly cross platform. Xcode with agent use has been really nice to work with, and t3.code support for emulators has been amazing to use.

What is benefit of GPU-rendered UI? In regular 2d apps where I can select enable/disable GPU rendering, disabling doesn't make app feel slower, but it drastically reduces RAM and VRAM usage (VRAM is the one I care about, as I run local models). Why so many UI frameworks brag that they are GPU-rendered?

  • Well, for one, it usually is much more energy-efficient: longer battery life, cooler computers, and more responsive under heavy (CPU) load.

  • Other people have different hardware and different goals. A year or so ago I worked on a Linux laptop that was dog-slow. If I didn't enable GPU-rendering for the UI, it competed for the very limited CPU.

  • Using less power is generally the main benefit. On lower end hardware you may also notice a performance difference, depending on what the UI is trying to display.

> native GPU-rendered Rust UI

Sorry, what? I feel like I've studied the Rust UI ecosystem pretty well, and the examples look nice, but if I've learned anything it's that "native" and "GPU-rendered" are oxymoronic.

Likely the fonts will be fuzzy on various platforms, accessibility will be under-baked and it will land in the bucket with every other UI framework depending on winit. I like the personalities at anomaly, but I'm quite confused about what's even driving a decision to build something like this versus contributing to egui, GPUI, Iced, etc.

  • It's definitely possible to do sharp fonts in the Rust GUI ecosystem (although you certainly won't get it out of the box). With the native text libraries if you want to (both Servo, Zed/GPUI, and anything using Skia do this), or emulated with Skrifa + Vello.

    But I agree with the reset

  • Yeah. Presumably "native" here just means "not Electron", which is the sales pitch for most AI-generated Rust libraries these days. ("Tell your agent to rewrite your Electron app into Rust~! :rocket emoji:")

When I made my ow GPU-renderered framework I found that it was possible to render the entire UI in one call/shader to the UI. All primitives and styles can be passed as a updatable data blob that the single GPU shader handles in one call. Do most of the GPU-rendered frameworks do it this way?

It has some tradeoffs to consider but seems quite good overall.

Re: Use it with your agent

An approach I've found useful, albeit for a DSL that ships a binary for execution, is to give a way for the LLM agent to get a high-level topic list so it can drill down all the way to specific language/API implementation details.

Perhaps with this project the author could make a website that does the same?

Broadly: In what circumstances, use cases, preferences etc would I use this instead of EGUI or GPUI?

The double-edged sword of choice!

  • I'd like to know this too. I'm building a egui app and it's fantastic. I have tons of custom drawing and stuff though

It would be fun to port some apps over to this, I'm worried at the speed it moves, It would be hard to settle on a commit. I'd rather fast updates over slow, but I feel like I'd have very little trust on this between updates, especially how many things could be broken after updating.

What does "native" mean to these people. Native UI means using the widgets provided by the operating system. This is not that.

  • Changing times. Nowadays a lot of software UIs are developed by people with a web UI background. Those people won’t learn the OS-native UIs because that would mean they’d give up on their existing knowledge. Because of that native means “not running in an embedded web browser” to many nowadays.

  • I have the same annoyance. It's continually maddening to see "native" plastered everywhere only for it to be some non-native junk. I miss when native meant something like Qt.

    • Qt is an interesting case, because it doesn't use the native platform's widget code*, but does a good job of looking and behaving as though it does. That's usually close enough for me.

      Various other toolkits have tried this approach, but unfortunately, I'm not aware of any others that succeed. Common deficiencies include keyboard navigation and text rendering.

      *(Except on Qt-based desktops like KDE Plasma, of course.)

  • I've been thinking a lot about the term "native" as I come from mobile. When writing a core in Rust (which I like to do), and then layering on the operating system's UI SDK components per platform (which I also like to do), what is native and what isn't, especially when you throw in React Native to the discussion?

    I like your definition quite a bit, but I need another word for, "code that doesn't need a runtime to execute."

    I ended up using "experience layer" to describe the SDK components.

  • Native often means "not a wrapper around a webview".

    If you define it as "using the widgets provided by the operating system", then "native" is by definition incompatible with "cross-platform." And what does that mean on Linux, where the operating system doesn't provide widgets? Are gtk and Qt not native?

    • Adding to this...

      When discussing GUI toolkits, "native" should be understood to mean "native to the host's graphical environment".

      "Native to the OS" might or might not be equivalent, depending on the OS and what one considers "OS" to mean. (Does it mean a kernel? A desktop distro? Something else?) Because of this ambiguity, it's not a very practical way to approach the discussion. Different people attach different meanings to that phrase.

      Some frameworks are native to Qt. Others are native to Gtk. Practically none are native to Linux. ;)

      I don't think "cross-platform" is incompatible with "native". It has been achieved more than once using toolkit wrappers, usually selected at build time.

The dynamic lighting setup is pretty cool. Not sure how practical it is for most applications but cool.

But this syntax – egads man! It literally hurts my brain trying to parse it:

    fn view(s: &State, _: &mut Cx<State>) -> El {
        let t = tok::theme(true);
        let label = text(if s.on { "Lights on" } else { "Lights off" })
        .font(type_::TITLE).color(t.text);
        let knob = el().key("knob").size(18.0, 18.0).radius(9.0).fill(t.knob)
            .absolute(if s.on { 18.0 } else { 2.0 }, 2.0);
        let switch = el().key("switch").role("switch").label("Lights").checked(s.on)
            .focusable(true).size(38.0, 22.0).radius(11.0)
            .fill(if s.on { tok::accent(0, true) } else { t.control_off })
            .motion(motion::SNAPPY)
            .on_press(|s: &mut State| s.on = !s.on)
            .child(knob);
        col().w_full().h_full().center().gap(16.0).fill(t.bg).child(label).child(switch)
    }

Maybe I'm getting too old but I'd prefer good old Perl 5 linenoise.

why are we giving more accessibility to agents than to like disabled human users?

  • I wonder whether that results in better accessibility for disabled people in the end because agents can control UIs for them.

This is from the same guys that thought building a coding agent harness with "Bun" was a good idea

This is what a vibe coded UI framework looks like.

Have a read of the clean documentation that they never wrote or read. [0]

All the clean code, architecture principles thrown out of the window in favour of hundreds of code smells, anti-patterns, zero tests, and tons of unmaintainable slop.

[0] https://github.com/anomalyco/rune/blob/dev/crates/rune/READM...

...what does this do? Is it just a vibecoded version of https://www.egui.rs/