GitHub - aprillz/MewUI: A cross-platform and lightweight, code-first .NET GUI framework aimed at NativeAOT.

🎗️ In loving memory of my beloved cat and companion, April. Forever in my heart.

2012.04.15 – 2026.06.20

사랑하는 사월아, 내 곁에 와줘서 고마워. 너와 함께한 모든 순간이 행복했단다.
꼭 다시 만나자. 내 보물 송사월.

My beloved April, thank you for coming into my life, and I was always so happy.
We will surely meet again. My treasure, April.

😺 MewUI is a cross-platform, lightweight, code-first .NET GUI framework for building and shipping NativeAOT/Trim-friendly desktop apps without requiring a separate .NET runtime installation.

Note

The official pronunciation of MewUI is /mjuː aɪ/ (“myoo-eye”).

Project Status: Active Development

Important

MewUI is an actively developed framework with published NuGet packages, cross-platform hosts, multiple rendering backends, and optional extension packages.

The public API surface is still being stabilized, so breaking changes can happen between minor releases. For production apps, pin package versions and review release notes before upgrading.

🤖 AI-Assisted Development

Note

This project was developed using an AI prompt–driven workflow.
Design and implementation were performed through iterative prompting without direct manual code edits,
with each step reviewed and refined by the developer.

🚀 Try It Out

No clone. No download. No project setup.
You can run MewUI immediately with a single command on Windows, Linux or macOS. (.NET 10 SDK required)

Tip

This is the quickest way to try MewUI without going through the usual repository and project setup steps.

curl -sL https://raw.githubusercontent.com/aprillz/MewUI/refs/heads/main/samples/FBASample/fba_gallery.cs -o - | dotnet run -

Warning

This command downloads and executes code directly from GitHub.

Video

MewUI.Showcase.mp4

Screenshots

Light	Dark

✨ Highlights

📦 NativeAOT + trimming first
🪶 Lightweight by design (small EXE, low memory footprint, fast first frame)
🧩 Fluent C# markup (no XAML)

🚀 Quickstart

NuGet: https://www.nuget.org/packages/Aprillz.MewUI/
- Aprillz.MewUI is a metapackage that bundles Core, all platform hosts, and all rendering backends.
- Platform-specific packages are also available: Aprillz.MewUI.Windows, .Linux, .MacOS
- Install: dotnet add package Aprillz.MewUI
- See: Installation & Packages

Single-file app (VS Code friendly)

See: samples/FBASample/fba_calculator.cs

Minimal header (without AOT/Trim options):

#:sdk Microsoft.NET.Sdk
#:property OutputType=Exe
#:property TargetFramework=net10.0

#:package Aprillz.MewUI

// ...

Run: dotnet run your_app.cs

🧪 C# Markup at a Glance

Sample source: https://github.com/aprillz/MewUI/blob/main/samples/MewUI.Sample/Program.cs

 var window = new Window()
     .Title("Hello MewUI")
     .Size(520, 360)
     .Padding(12)
     .Content(
         new StackPanel()
             .Spacing(8)
             .Children(
                 new Label()
                     .Text("Hello, Aprillz.MewUI")
                     .FontSize(18)
                     .Bold(),
                 new Button()
                     .Content("Quit")
                     .OnClick(() => Application.Quit())
             )
     );

 Application.Run(window);

🎯 Concept

MewUI is a code-first GUI framework with a small, explicit core and platform-specific hosts/backends.

NativeAOT + trimming friendliness
Small footprint, fast startup, low memory usage
Fluent C# markup for building UI trees (no XAML)
AOT-friendly explicit binding
Thin core, optional extensions for larger features

Non-goals (by design):

Full XAML/WPF compatibility
A drop-in replacement for WPF or Avalonia with identical APIs and behavior
Designer-first development workflows
Complex path-based data binding
An exhaustive, all-in-one control catalog

The core covers common desktop UI patterns; specialized features such as charts and docking ship as extension packages.

✂️ NativeAOT / Trim

The library aims to be trimming-safe by default (explicit code paths, no reflection-based binding).
Windows interop uses source-generated P/Invoke (LibraryImport) for NativeAOT compatibility.
On Linux, building with NativeAOT requires the AOT workload in addition to the regular .NET SDK (e.g. install dotnet-sdk-aot-10.0).
If you introduce new interop or dynamic features, verify with the trimmed publish profile above.

NativeAOT executable size depends on the platform host, rendering backend, resources, and publish options. The table below measures the main executable only; ZIP is the same executable compressed with the default measurement settings. Sizes use binary units: 1 MB = 1024 KB.

Sample	Platform / backend	Executable	ZIP
Hello World	Windows x64 / GDI	2.907 MB	1.324 MB
Hello World	Windows x64 / Direct2D	3.046 MB	1.381 MB
Hello World	Windows x64 / MewVG	3.211 MB	1.458 MB
Hello World	Linux x64 / X11 + MewVG	4.414 MB	2.126 MB
Hello World	macOS arm64 / MewVG	2.635 MB	1.186 MB
Gallery	Windows x64 / GDI	5.838 MB	2.564 MB
Gallery	Windows x64 / Direct2D	5.959 MB	2.612 MB
Gallery	Windows x64 / MewVG	6.176 MB	2.707 MB
Gallery	Linux x64 / X11 + MewVG	7.420 MB	3.518 MB
Gallery	macOS arm64 / MewVG	5.625 MB	2.555 MB

The Gallery is a full-featured showcase sample. Use the Hello World rows as the minimum deployment-size baseline.

🔗 State & Binding (AOT-friendly)

Bindings are explicit and delegate-based (no reflection):

using Aprillz.MewUI.Binding;
using Aprillz.MewUI.Controls;

var percent = new ObservableValue<double>(
    initialValue: 0.25,
    coerce: v => Math.Clamp(v, 0, 1));

var slider = new Slider()
            .BindValue(percent);
var label  = new Label()
            .BindText(percent, v => $"Percent ({v:P0})");

🧱 Controls / Panels

Controls (Implemented):

Button, ToggleButton
Label, TextBlock, Image
TextBox, MultiLineTextBox, PasswordBox
CheckBox, RadioButton, ToggleSwitch
ComboBox, ListBox, TreeView, GridView
Slider, ProgressBar, ProgressRing, NumericUpDown
TabControl, GroupBox, Expander, Border
ColorPicker, DatePicker, Calendar
MenuBar, ContextMenu, ToolTip (in-window popups)
ScrollViewer
Window, DispatcherTimer

Panels:

Grid (rows/columns with Auto, *, pixel)
StackPanel (horizontal/vertical)
DockPanel (dock edges + last-child fill)
UniformGrid (equal cells)
WrapPanel (wrap + item size)
Canvas (absolute positioning)
SplitPanel (drag splitter)

All panels except Canvas (absolute) and SplitPanel support Spacing.

🧩 Extensions

Optional packages layered on top of the core - reference only what you need.

Extension	Description	Package
MewDock	Visual Studio style docking - document/tool tabs, drag rearranging, splits, auto-hide, maximize, popouts	`Aprillz.MewUI.MewDock`
SVG	Pure C# SVG parsing/rendering (no System.Drawing, AOT compatible)	`Aprillz.MewUI.Svg`
Skia	`SkiaCanvasView` (draw with SkiaSharp) + GPU zero-copy interop	`Aprillz.MewUI.Skia`
MewCharts	Charts (Cartesian/Pie/Polar) via the LiveChartsCore engine, no SkiaSharp dependency	`Aprillz.MewUI.MewCharts`
WebView2	Win32 WebView2 control (requires the Microsoft Edge WebView2 runtime, Windows only)	`Aprillz.MewUI.WebView2.Win32`

Skia interop - add the zero-copy bridge matching your backend to enable the GPU fast path.

Backend	Package
Direct2D	`Aprillz.MewUI.Skia.Interop.Direct2D`
GDI	`Aprillz.MewUI.Skia.Interop.Gdi`
MewVG / Win32	`Aprillz.MewUI.Skia.Interop.MewVG.Win32`
MewVG / X11	`Aprillz.MewUI.Skia.Interop.MewVG.X11`
MewVG / macOS	`Aprillz.MewUI.Skia.Interop.MewVG.MacOS`

Without an interop package, Skia content still renders via the CPU upload fallback. Skia is also bundled as metapackages Aprillz.MewUI.Skia.Windows / .Linux / .MacOS / .All.

MewDock is a C# port of FlexLayout (MIT). MewCharts bundles the LiveChartsCore engine (MIT). See THIRD_PARTY_NOTICES.md for license notices.

🎨 Theme

MewUI uses a Theme object (colors + metrics) and ThemeManager to control defaults and runtime changes.

Configure defaults before Application.Run(...) via ThemeManager.Default*
Change at runtime via Application.Current.SetTheme(...) / Application.Current.SetAccent(...)

See: docs/Theme.md

🖌️ Rendering Backends

Rendering is abstracted through:

IGraphicsFactory / IGraphicsContext

Backends:

Backend	Platform	Package
Direct2D	Windows	`Aprillz.MewUI.Backend.Direct2D`
GDI	Windows	`Aprillz.MewUI.Backend.Gdi`
MewVG	Windows	`Aprillz.MewUI.Backend.MewVG.Win32`
MewVG	Linux/X11	`Aprillz.MewUI.Backend.MewVG.X11`
MewVG	macOS	`Aprillz.MewUI.Backend.MewVG.MacOS`

MewVG is a managed port of NanoVG, using OpenGL on Windows/Linux and Metal on macOS.

Backends are registered by the referenced backend packages (Trim/AOT-friendly). In app code you typically either:

call *Backend.Register() before Application.Run(...), or
use the builder chain: Application.Create().Use...().Run(...)

When using a metapackage (e.g., Aprillz.MewUI.Windows), you can select a single backend at publish time with -p:MewUIBackend=Direct2D. See Installation & Packages for details.

🪟 Platform Abstraction

Windowing and the message loop are abstracted behind a platform layer.

Currently implemented:

Windows (Aprillz.MewUI.Platform.Win32)
Linux/X11 (Aprillz.MewUI.Platform.X11)
macOS (Aprillz.MewUI.Platform.MacOS)

Linux dialogs dependency

On Linux, MessageBox and file dialogs are currently implemented via external tools:

zenity (GNOME/GTK)
kdialog (KDE)

If neither is available in PATH, MewUI throws: PlatformNotSupportedException: No supported Linux dialog tool found (zenity/kdialog).

📄Docs

🤝 Community

🧭 Roadmap

Platforms

Linux/Wayland
Linux framebuffer

Tooling

Hot Reload (experimental)
Design-time preview

License

MewUI is licensed under the MIT License.

Third-party software notices are available in THIRD_PARTY_NOTICES.md.

Name		Name	Last commit message	Last commit date
Latest commit History 1,146 Commits
.github		.github
assets		assets
build		build
docs		docs
extensions		extensions
meta		meta
samples		samples
src		src
tests		tests
tools		tools
.editorconfig		.editorconfig
.gitattributes		.gitattributes
.gitignore		.gitignore
.gitmodules		.gitmodules
CODE_OF_CONDUCT.ko.md		CODE_OF_CONDUCT.ko.md
CONTRIBUTING.ko.md		CONTRIBUTING.ko.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
MewUI.slnx		MewUI.slnx
NUGET_README.md		NUGET_README.md
README.ko.md		README.ko.md
README.md		README.md
THIRD_PARTY_NOTICES.md		THIRD_PARTY_NOTICES.md

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Project Status: Active Development

🤖 AI-Assisted Development

🚀 Try It Out

Video

Screenshots

✨ Highlights

🚀 Quickstart

🧪 C# Markup at a Glance

🎯 Concept

Non-goals (by design):

✂️ NativeAOT / Trim

🔗 State & Binding (AOT-friendly)

🧱 Controls / Panels

🧩 Extensions

🎨 Theme

🖌️ Rendering Backends

🪟 Platform Abstraction

Linux dialogs dependency

📄Docs

🤝 Community

🧭 Roadmap

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Project Status: Active Development

🤖 AI-Assisted Development

🚀 Try It Out

Video

Screenshots

✨ Highlights

🚀 Quickstart

🧪 C# Markup at a Glance

🎯 Concept

Non-goals (by design):

✂️ NativeAOT / Trim

🔗 State & Binding (AOT-friendly)

🧱 Controls / Panels

🧩 Extensions

🎨 Theme

🖌️ Rendering Backends

🪟 Platform Abstraction

Linux dialogs dependency

📄Docs

🤝 Community

🧭 Roadmap

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