Context
ModernWpfUI 0.9.6 is unmaintained (last update 2022). Evaluate lepoco/wpfui as a replacement.
Findings
Library Overview
- Stars: ~9.4k, actively maintained
- Latest release: v4.3.0 (May 2026)
- License: MIT
- .NET 9 support: Yes (since v4.0.0; .NET 10 in v4.1.0)
- Fluent Design: Windows 11 Mica backdrop, Snap Layout, WinUI 3-style controls
Pros
- Actively maintained with regular releases
- Full .NET 9/.NET 10 support
- Windows 11 native look (Mica, acrylic, rounded corners)
- Built-in DI/hosting support (compatible with our Microsoft.Extensions.DependencyInjection pattern)
- Modern controls not in ModernWpfUI (NavigationView, NumberBox, InfoBar, Snackbar)
- Large community (9.4k stars)
Cons / Risks
- No official migration guide from ModernWpfUI
- Navigation model is opinionated (page-based NavigationView) — may conflict with sidebar tabs approach
- Theme system modifies base WPF elements — possible clash with custom styles
- 405 open issues on GitHub (some edge cases)
- Breaking changes between major versions (v3 → v4 had API changes)
Breaking Changes Expected
| Area |
ModernWpfUI (current) |
WPF-UI (target) |
| XAML namespace |
xmlns:ui="http://schemas.modernwpf.com/2019" |
xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml" |
| Theme resources |
<ui:ThemeResources/> |
<ui:ThemesDictionary Theme="Dark"/> |
| Controls resources |
<ui:XamlControlsResources/> |
<ui:ControlsDictionary/> |
| Window style |
WindowHelper.UseModernWindowStyle |
FluentWindow base class or WindowBackdropType |
Migration Effort: Small
Our ModernWpfUI usage is minimal (3 touchpoints):
App.xaml — ThemeResources + XamlControlsResources (2 lines)MainWindow.xaml — WindowHelper.UseModernWindowStyle (1 line)- Namespace declarations in ~4 files
We have a fully custom design system that overrides most defaults. Migration is essentially: swap NuGet, change namespaces, update 2 resource lines, update window style.
Estimated time: 1–2 hours including testing.
Recommendation: Migrate
Risk is low (tiny ModernWpfUI surface area). Benefits: continued maintenance, .NET 9/10 support, modern Fluent controls available. Staying on 0.9.6 accumulates compatibility debt.
Next Steps
Context
ModernWpfUI 0.9.6 is unmaintained (last update 2022). Evaluate lepoco/wpfui as a replacement.
Findings
Library Overview
Pros
Cons / Risks
Breaking Changes Expected
xmlns:ui="http://schemas.modernwpf.com/2019"xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml"<ui:ThemeResources/><ui:ThemesDictionary Theme="Dark"/><ui:XamlControlsResources/><ui:ControlsDictionary/>WindowHelper.UseModernWindowStyleFluentWindowbase class orWindowBackdropTypeMigration Effort: Small
Our ModernWpfUI usage is minimal (3 touchpoints):
App.xaml— ThemeResources + XamlControlsResources (2 lines)MainWindow.xaml—WindowHelper.UseModernWindowStyle(1 line)We have a fully custom design system that overrides most defaults. Migration is essentially: swap NuGet, change namespaces, update 2 resource lines, update window style.
Estimated time: 1–2 hours including testing.
Recommendation: Migrate
Risk is low (tiny ModernWpfUI surface area). Benefits: continued maintenance, .NET 9/10 support, modern Fluent controls available. Staying on 0.9.6 accumulates compatibility debt.
Next Steps
feat/wpfui-migration