In-Depth Comparison of Mainstream Open-Source C# GUI Frameworks: Avalonia UI, .NET MAUI, Uno Platform, Eto.Forms, GtkSharp

Forum topic · ✨步子哥 · 2026-02-15

Summary

A data-driven comparison of five mainstream open-source C# GUI frameworks — Avalonia UI, .NET MAUI, Uno Platform, Eto.Forms, and GtkSharp — based on GitHub metrics, community health, release cadence, funding, licensing, enterprise adoption, and developer experience as of February 2026. Avalonia UI leads with 30.1k stars, 450+ contributors, the best issue-resolution ratio (1:3.7), and a $3M Devolutions sponsorship underpinning a MIT-licensed core plus commercial XPF/Accelerate products; it is used by GitHub, JetBrains, AMD, Boeing, and Icons8's Lunacy. .NET MAUI (23.2k stars) benefits from Microsoft backing and full .NET integration but lacks Linux support and shows slowing growth. Uno Platform (9.8k stars) covers mobile, desktop, WebAssembly, and embedded targets with ~95% WinUI API compatibility, backed by C$3.5M seed funding and clients like Toyota and TradeZero. Eto.Forms remains a lightweight, single-maintainer option suited to embedded tool UIs, while GtkSharp is effectively dormant with no release since 2021 and is not recommended for new projects.

In-Depth Comparison of Mainstream Open-Source C# GUI Frameworks

*Structured summary of a long-form Chinese forum post comparing five C# GUI frameworks as of February 15, 2026. Figures are as reported in the original post.*

Key points

Avalonia UI is the community leader: 30.1k GitHub stars, 2.6k forks, 450+ contributors, ~15 full-time engineers, and the best issue-resolution health (open/closed ratio 1:3.7, median response 18h, Community Health Index ~1.85).
.NET MAUI has the biggest brand backing but slowing momentum: 23.2k stars, ~50 Microsoft staff, monthly service releases aligned to .NET patch cycles — but 3.8k open issues, no Linux support, and ~60% of merged code from Microsoft internally.
Uno Platform is the full-spectrum option: 9.8k stars, ~95% WinUI 3 API compatibility, mobile + desktop + WebAssembly + embedded coverage, fastest small-fix merge cycle (3–5 days), backed by C$3.5M seed funding and 100M+ cumulative NuGet downloads.
Eto.Forms is a niche, single-maintainer project: 3.9k stars, MIT-licensed, releases ~2/year; used as embedded UI in MonoGame, ScottPlot, NAPS2, OpenTabletDriver.
GtkSharp is effectively dead: 970 stars, last release April 2021 (1,780 days ago), no active governance — not recommended for new projects.

GitHub metrics snapshot

| Framework | Stars | Forks | Open Issues | Latest Release | Status | |---|---|---|---|---|---| | Avalonia UI | 30.1k | 2.6k | 1.9k | 11.3.12 (2026-02-12) | Very active | | .NET MAUI | 23.2k | 1.9k | 3.8k | 10.0.31 SR3.1 (2026-02-03) | Active | | Uno Platform | 9.8k | 836 | 1.4k | 6.5.64 (2026-02-11) | Very active | | Eto.Forms | 3.9k | 343 | 347 | 2.10.2 (2025-09-26) | Warning sign | | GtkSharp | 970 | 112 | 66 | 3.24.24.34 (2021-04-02) | Dormant |

Funding & licensing

Avalonia UI: $3M/3-year Devolutions sponsorship earmarked for the MIT-licensed core; commercial products are Avalonia XPF and the Accelerate tool suite (Indie €89/yr, Business €149, Enterprise €499).
Uno Platform: C$3.5M seed round (2025); open core (Apache 2.0) + paid Uno Platform Studio subscription; ARR reportedly passed $600k in late 2025.
.NET MAUI: fully funded by Microsoft, Apache 2.0, free.
Eto.Forms: no known funding; MIT. GtkSharp: no funding; complex MIT/LGPL mix.

Enterprise adoption

Avalonia UI: GitHub (experimental Linux desktop client), JetBrains (Rider plugin), AMD, Texas Instruments, Schneider Electric, Boeing, BAE Systems, Moody's, Canon, Air France KLM. Icons8's Lunacy design tool migrated from WPF, reporting ~3x faster development versus alternatives. XPF targets WPF-to-cross-platform migration with claimed 90%+ code reuse.
.NET MAUI: Microsoft first-party apps (To Do, Authenticator), Epic Systems patient portal migration, various regulated-industry internal apps.
Uno Platform: Toyota North America dealer systems (85% code reuse, 40% faster time-to-market), TradeZero trading platform (<50ms order latency), Jean-Coutu, Cineplex, iA Financial.
Eto.Forms / GtkSharp: Eto limited to embedded tool UIs; GtkSharp has essentially no verifiable commercial use.

Developer experience

Uno Platform: easiest path for UWP/WinUI developers (~3–5 days); ~95% XAML similarity.
Avalonia UI: friendliest for WPF developers (~1–2 weeks); ~85% XAML similarity; adds a CSS-like style selector system; ViewModel reuse often 95%+.
.NET MAUI: best for Xamarin developers (~2–4 weeks for WPF devs); new Handler architecture; richest official docs and learning resources.
Eto.Forms: code-first C# API option for WinForms-background developers; GtkSharp: requires learning GTK concepts (3–6 weeks), minimal resources.

Roadmaps (2025–2027)

Avalonia v12: Impeller rendering engine integration (targeting 12x lower GPU power draw), WebAssembly GA (startup <2s), further WPF feature parity in XPF.
Uno: Hot Design GA, AI-driven code generation, MCP integration, Skia backend and WASM cold-start optimization (target <1s).
.NET MAUI: Linux support being explored via cooperation with the Avalonia team; Blazor Hybrid maturation. Eto.Forms: no public roadmap. GtkSharp: none.

Bottom line

For cross-platform desktop work in the .NET ecosystem, Avalonia UI offers the strongest community, momentum, and WPF familiarity; Uno Platform is the choice for maximal platform reach from a WinUI-style codebase; .NET MAUI remains the safe official option where Microsoft support and mobile-first targets dominate; Eto.Forms serves lightweight embedded needs; GtkSharp should be avoided for new development.