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

Rune is a Rust UI framework for building native applications on macOS, Windows, and Linux, as well as web apps. It provides its own GPU renderer, text handling, layout system, and spring-based animations rather than relying on an existing UI toolkit. The example shows a declarative interface assembled from elements: a centered label and animated toggle switch whose appearance and checked state respond to user input. The repository also showcases more complex interfaces and effects, including a chat app, split-diff component, settings window, and liquid-metal rendering.

A central feature is headless operation: apps can render to PNG images, expose their element tree, and respond to scripted input without opening a visible window. This makes it possible for coding agents to inspect and test their work automatically. The maintainers recommend starting from the hello-world example and checking changes with those headless tools. Rune is pre-release, and users are advised to depend on a pinned revision of its development branch, which the project says is not rewritten. The repository is MIT-licensed and includes documentation, components, examples, and a changelog. Its contribution process is unusual: it does not accept pull requests and asks users to report bugs or ideas through issues, which its agents generally handle.