LavaUI

A declarative UI framework for Swift on Linux, with its own GPU renderer — and a Wayland desktop built on top of it.

struct Counter: View {
    @State private var count = 0

    var body: some View {
        VStack(padding: 8) {
            Text("count: \(count)", color: .accent)
            Text("[ increment ]", onClick: { count += 1 })
        }
    }
}

If you have written SwiftUI, this will look familiar: views are small structs with a body, state lives in @State, and the framework redraws what changed. Everything underneath — layout, text, rendering — is part of this repository.

The repo has two halves:

• The framework (LavaUI) — for writing desktop apps in Swift.
• The Lava desktop — a Wayland compositor with a panel, dock, launcher and a set of apps, all written with LavaUI. Ordinary Linux apps run on it too.

Linux only for now.

Quick start

On Debian or Arch:

git clone https://github.com/nikitapn/LavaUI.git && cd LavaUI
./scripts/bootstrap.sh --yes      # installs everything, builds everything
swift run HelloWorld              # the demo

docs/install.md explains what that does, and how to install only what the framework needs.

Using LavaUI in your app

Add the package to your Package.swift and open a window:

import LavaUI

@main
struct MyApp {
    static func main() {
        guard let editor = LavaApp.open(title: "My App") else { return }
        LavaApp.run(editor: editor) {
            Text("hello from LavaUI", color: .accent)
        }
    }
}

Getting started walks through it from an empty directory, including the one manifest setting the package needs.

Apps

Every one of these is a LavaUI app and runs with swift run <name>:

App	What it is
HelloWorld	Demo of the framework's views
LavaTerm	Terminal emulator
LavaEditor	Text editor
LavaExplorer	File manager — tabs, split panes, Trash
LavaPass	KeePass-compatible password vaults — guide
LavaView	Image viewer
LavaPDF	PDF reader
LavaPlayer	Video player
LavaSpotify	Spotify player
LavaWeather	Weather
TraceLoom	Log viewer with an AI assistant
LavaShot	Screenshot and annotation tool (needs the Lava desktop)

The desktop itself — LavaPanel, LavaDock, LavaLauncher, LavaSwitcher, LavaSettings — is made of LavaUI apps as well.

The Lava desktop

compositor/scripts/dev-run                       # try it in a window, inside your current session
compositor/scripts/start-lava-compositor setup   # install it as a real session

See compositor/README.md.

Documentation

Getting started	From an empty package to a running window
API guide	Views, layout, modifiers, theming, animation
SwiftUI parity	What carries over from SwiftUI and what differs
How it works	The rendering pipeline and the repo layout
Installing	Packages, Docker, the test VM
Performance	Benchmarks and baselines
AGENTS.md	The in-depth guide for contributors and coding agents

The docs site is at lavaui.nikitapn.com.

Built with

• Swift 6.4+ with C++ interop, and C++23 for the engine and compositor
• Vulkan — rendering
• Yoga — flexbox layout
• FreeType and HarfBuzz — fonts and text shaping
• GLFW — windows, when an app runs on its own
• wlroots — the compositor
• NPRPC — communication between apps and the compositor
• poppler (PDF), libmpv (video), libarchive (archives), librsvg (icons)

The full package lists are in packaging/deps/.

License

MIT — see LICENSE.