C# GUI Open-Source Frameworks Deep Comparison: Avalonia UI, .NET MAUI, Uno Platform, Eto.Forms, and GtkSharp

Forum topic · ✨步子哥 · 2026-02-15

Summary

This comparative analysis evaluates five major open-source C# GUI frameworks—Avalonia UI, .NET MAUI, Uno Platform, Eto.Forms, and GtkSharp—based on GitHub metrics, community activity, maintenance health, corporate adoption, and developer experience. As of mid-February 2026, Avalonia UI leads with 30.1k GitHub Stars and an exceptional Community Health Index (CHI) of 1.85, supported by a $3M Devolutions sponsorship. .NET MAUI follows with 23.2k Stars under Microsoft's official stewardship but shows slowing growth and Linux support gaps. Uno Platform demonstrates strong momentum with VC backing (C$3.5M) and AI-first tooling. Eto.Forms serves niche cross-platform needs with limited cadence, while GtkSharp is effectively abandoned after nearly 5 years without releases. Key findings include enterprise endorsements from GitHub, JetBrains, Tesla, Boeing, AMD, Toyota, and Toyota, plus ecosystem strengths across MVVM, Syncfusion, and Telerik suites.

Overview

Comprehensive comparative analysis of five mainstream C# GUI frameworks based on GitHub metrics, community health, maintenance status, enterprise adoption, and development experience as of February 15, 2026.

Key points

1. GitHub Core Metrics and Community Activity

#### 1.1 Stars Ranking and Growth Trends

| Framework | Stars | First Release | Stars/Year | 2024-2025 Growth | Market Position | |:---|:---|:---|:---|:---|:---| | Avalonia UI | 30.1k | 2013 | ~2,300 | High (continuously accelerating) | Enterprise cross-platform desktop leader | | .NET MAUI | 23.2k | 2022 (GA) | ~7,700 | Moderate (slowing) | Official mobile+desktop framework | | Uno Platform | 9.8k | 2018 | ~1,400 | High (technology-driven) | Full-platform enterprise solution | | Eto.Forms | 3.9k | 2012 | ~325 | Very low (stabilizing) | Lightweight cross-platform alternative | | GtkSharp | 970 | 2001 (Gtk# era) | ~45 | Stagnant (near-zero growth) | Legacy project maintenance mode |

Avalonia UI leads with continuous acceleration: ~8k Stars in 2020, 20k+ by 2023, 30k+ by early 2026, with CAGR exceeding 25%.
.NET MAUI shows brand-backed momentum but slowing growth due to concerns about missing Linux support and mobile platform maturity.
Uno Platform benefits from Hot Design and other innovations driving renewed Star growth.
GtkSharp sits at the bottom, signaling marginalization in the C# ecosystem.

#### 1.2 Forks and Community Participation

| Framework | Forks | Fork/Star Ratio | Contributor Scale | |:---|:---|:---|:---| | Avalonia UI | 2.6k | 8.6% | 450+ | | .NET MAUI | 1.9k | 8.2% | Microsoft official team | | Uno Platform | 836 | 8.5% | 300+ | | Eto.Forms | 343 | 8.8% | Individual-led | | GtkSharp | 112 | 11.5% | Unclear |

Avalonia UI's modular rendering backend enables accessible contribution.
Over 60% of .NET MAUI's merged code comes from Microsoft internal teams.
Uno Platform demonstrates high Fork-to-PR conversion (~20%), exceeding open-source norms.

#### 1.3 Issues and PR Activity

| Framework | Open Issues | Open/Closed Ratio | 90-Day Median Response | |:---|:---|:---|:---| | .NET MAUI | 3.8k | 1:3.2 | 48h | | Avalonia UI | 1.9k | 1:3.7 | 18h | | Uno Platform | 1.4k | 1:3.9 | 24h | | Eto.Forms | 347 | 1:3.2 | 72h | | GtkSharp | 66 | 1:3.0 | 240h+ |

| Framework | Active PRs | Avg Merge Cycle | Merge Rate | |:---|:---|:---|:---| | .NET MAUI | 642 | 7-14 days | ~78% | | Uno Platform | 119 | 3-5 days | ~85% | | Avalonia UI | 67 | 10-20 days | ~92% | | Eto.Forms | 13 | Days to months | ~88% | | GtkSharp | 9 | No mergers | ~44% |

Community Health Index (CHI): Avalonia UI leads at 1.85 (problems absorbed faster than created), followed by Uno Platform (1.52), Eto.Forms (0.95), .NET MAUI (0.72), and GtkSharp (0.15 — severe crisis).

#### 1.4 Community Channels

Avalonia UI: ~15,000 members across Telegram, Discord, and GitHub Discussions; 500+ daily messages; founder direct engagement.
Uno Platform: ~8,000 Discord members; executive-direct support with fixed office hours.
.NET MAUI: ~50,000 on Microsoft Learn forums; Stack Overflow ~15k maui-tagged questions.
Stack Overflow answer rates: Avalonia UI 72%, .NET MAUI 68%, Uno Platform 65%, Eto.Forms 58%, GtkSharp 45%.

2. Project Health and Maintenance

#### 2.1 Latest Version and Release Cadence

| Framework | Latest Version | Date | Days Ago | Status | |:---|:---|:---|:---|:---| | Avalonia UI | 11.3.12 | 2026-02-12 | 3 | ⭐⭐⭐⭐⭐ Extremely active | | Uno Platform | 6.5.64 | 2026-02-11 | 4 | ⭐⭐⭐⭐⭐ Extremely active | | .NET MAUI | 10.0.31 SR3.1 | 2026-02-03 | 12 | ⭐⭐⭐⭐☆ Active | | Eto.Forms | 2.10.2 | 2025-09-26 | 142 | ⭐⭐⭐☆☆ Warning | | GtkSharp | 3.24.24.34 | 2021-04-02 | 1,780 | ⭐☆☆☆☆ Critical |

Avalonia UI's 11.3.x series released 12 patches since June 2025 (~1 every 2 weeks).
.NET MAUI follows monthly Patch Tuesday cadence.
Uno Platform delivers continuous deployment, ~64 builds in 2025.
Eto.Forms shows declining release frequency (2 in 2024 vs. 6 in 2023).

#### 2.2 Maintenance Teams and Funding

| Framework | Core Team | Governance | Funding | Model | |:---|:---|:---|:---|:---| | Avalonia UI | ~15 FT + 450+ PT | Incorporated (Avalonia UI Inc.) | $3M / 3 years (Devolutions) | Dual-license (MIT core + commercial) | | Uno Platform | ~25 FT + 300+ PT | VC-backed startup | C$3.5M seed | Open core + Studio subscription | | .NET MAUI | ~50 FT (Microsoft) | Corporate division | Undisclosed (~$tens of millions/year) | Free, ecosystem lock-in | | Eto.Forms | 1 (Curtis Wensley) | BDFL individual | None | Pure donation | | GtkSharp | Unclear | Undefined | None | None |

Notable: Avalonia UI's Devolutions firewall dedicates $3M exclusively to MIT-licensed framework development.

#### 2.3 Licensing

MIT: Avalonia UI, Eto.Forms, GtkSharp (with LGPL components).
Apache 2.0: .NET MAUI (with Microsoft CLA), Uno Platform (with patent grant and CLA).

#### 2.4 Roadmap Transparency

High: Avalonia UI (public GitHub Projects + blog; v12 targets WASM GA Q2 2026, Impeller integration, XPF feature parity); Uno Platform (quarterly roadmap livestreams; Hot Design GA, AI-driven code generation).
Medium: .NET MAUI (follows .NET release cadence).
Low/None: Eto.Forms, GtkSharp.

3. Ecosystem and Commercial Adoption

#### 3.1 Notable Enterprise Users

Avalonia UI adopters:

Software/developer tools: GitHub, JetBrains, Unity
Semiconductor/hardware: AMD, Texas Instruments
Industrial automation: Schneider Electric
Aerospace/defense: Boeing, BAE Systems
Financial analytics: Moody's Analytics, Datadog
Aviation services: Air France KLM
Imaging/printing: Canon

High-end Avalonia XPF customers: Tesla, Boeing, Texas Instruments, BAE Systems — promising "months-not-years" migration of legacy WPF codebases.

.NET MAUI production deployments: Microsoft internal apps (To Do, Authenticator, Family Safety); Salesforce offline data sync; Epic Systems patient portal mobile migration; multiple undisclosed bank internal tools.

Uno Platform adopters:

Toyota: North American dealer management with 85% code reuse, 40% faster time-to-market.
TradeZero: Stock trading platform with <50ms order latency after Skia + memory pool optimization.
Microsoft: Internal projects and Windows Community Toolkit extension.
Jean-Coutu, Cineplex, iA Financial in Canadian market.

Eto.Forms embedded users: MonoGame (13.2k Stars), ScottPlot (6.4k), NAPS2 (4.0k), OpenTabletDriver (3.6k), ZXing.Net (3.0k).

GtkSharp: Effectively zero modern commercial adoption.

#### 3.2 Featured Case Studies

Lunacy (Icons8) on Avalonia UI:

Migrated from WPF to cross-platform.
Skia rendering sustains 60fps with 10,000+ layers.
Apple Store / Microsoft Store dual release.
Estimated 3x faster than alternative frameworks.
Team describes Avalonia as "better WPF".

UXDivers embedded HMI on Avalonia UI:

CSS-like style selectors with pseudo-classes (:storm, :sunny).
TabControl lazy loading.
Linux Framebuffer + DRM/KMS backend for <3-second startup on hardware without X11/Wayland.

#### 3.3 NuGet and Third-Party Ecosystem

| Framework | Core Package | Total Downloads | Current Version Downloads | |:---|:---|:---|:---| | Uno Platform | Uno.Sdk | 100M+ cumulative | Undisclosed | | Eto.Forms | Eto.Forms | 1.2M | 9.6K | | Avalonia UI | Avalonia | Tens of millions (est.) | Undisclosed | | .NET MAUI | Microsoft.Maui | N/A (with .NET SDK) | N/A | | GtkSharp | GtkSharp | Negligible | Negligible |

MVVM/UI library support matrix:

| Library | Avalonia UI | .NET MAUI | Uno Platform | Eto.Forms | GtkSharp | |:---|:---|:---|:---|:---|:---| | ReactiveUI | ✅ Official | ✅ | ✅ | ⚠️ Community | ❌ | | CommunityToolkit.Mvvm | ✅ Recommended | ✅ Official | ✅ | ⚠️ Manual | ❌ | | Prism | ✅ Full | ✅ | ✅ Full | ❌ | ❌ | | Syncfusion | ✅ Full | ✅ Full | ✅ Full | ❌ | ❌ | | Telerik UI | ✅ Full | ✅ Full | ✅ Full | ❌ | ❌ | | Material Design | ✅ Official | ✅ Community | ✅ Official | ❌ | ⚠️ Limited | | Fluent Design | ✅ Native | ✅ Native | ✅ Native | ❌ | ❌ |

4. Developer Experience

#### 4.1 XAML Similarity and Migration Difficulty

| Framework | XAML Similarity | API Compatibility | Estimated Learning Time | Best For | |:---|:---|:---|:---|:---| | Uno Platform | ~95% | Very high (targets WinUI 3 subset) | 3-5 days | UWP/WinUI developers | | Avalonia UI | ~85% | High (namespace changes) | 1-2 weeks | WPF developers | | .NET MAUI | ~70% | Medium (mobile-first refactor) | 2-4 weeks | Xamarin developers | | Eto.Forms | N/A (code-first option) | Low | 1-2 weeks | WinForms background | | GtkSharp | N/A | Very low | 3-6 weeks | GTK concept learning required |

Uno Platform: ~99% of XAML compiles through; ~10-15% platform adjustment in real projects.
Avalonia UI: CSS-like selectors introduce modern flexibility but require ~15-25% XAML adjustment with ~95%+ ViewModel reuse from WPF.
.NET MAUI: Handler architecture redesign, new layout system, implicit binding context.

#### 4.2 Learning Resources

| Dimension | Avalonia UI | .NET MAUI | Uno Platform | Eto.Forms | GtkSharp | |:---|:---|:---|:---|:---|:---| | Official Tutorials | ⭐⭐⭐⭐☆ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐☆ | ⭐⭐⭐☆☆ | ⭐⭐☆☆☆ | | API Reference | ⭐⭐⭐⭐⭐ (85%) | ⭐⭐⭐⭐⭐ (95%) | ⭐⭐⭐⭐☆ (80%) | ⭐⭐⭐☆☆ (60%) | ⭐⭐☆☆☆ (40%) | | Advanced Topics | ⭐⭐⭐⭐⭐ | ⭐⭐⭐☆☆ | ⭐⭐⭐⭐☆ | ⭐⭐☆☆☆ | ⭐☆☆☆☆ | | Video/Courses | ⭐⭐⭐⭐☆ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐☆ | ⭐⭐☆☆☆ | ⭐☆☆☆☆ | | Chinese Resources | ⭐⭐⭐⭐☆ (fast growing) | ⭐⭐⭐⭐⭐ (official) | ⭐⭐⭐☆☆ | ⭐⭐☆☆☆ | ⭐☆☆☆☆ |

Key takeaways:

Avalonia UI documentation underwent major 2023-2024 Docusaurus rebuild.
Uno Platform plus .NET MAUI offer richest Chinese-language content.
GtkSharp remains effectively undocumented for new learners.

Recommendations

Enterprise cross-platform desktop: Avalonia UI — best for WPF migration, Linux support, and active maintenance.
Microsoft-aligned mobile+desktop: .NET MAUI — best ecosystem integration but accept no Linux support.
Full-platform (mobile/desktop/WASM/embedded): Uno Platform — best when code reuse spans all targets, especially with AI-assisted tooling.
Lightweight cross-platform niche: Eto.Forms — stable for embedded tooling; evaluate sustainability risk.
GTK legacy: GtkSharp — not recommended for new projects.