# OpenSilver/OpenSilver

Build Cross-Platform Apps with C#, VB.NET, or F# and XAML. One codebase. Six platforms. Powered by WebAssembly and .NET.

Repository: https://github.com/OpenSilver/OpenSilver
Canonical: https://ross.abutalabs.com/products/opensilver
Homepage: https://opensilver.net
Language: C#
License: NOASSERTION
License Family: other
Last push: 2026-08-24T15:08:19+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 2733, "days_push": 9, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1260, forks 132 (observed 2026-08-28T04:04:09.948551+00:00)

## What it is
OpenSilver is an open-source, MIT-licensed framework for building cross-platform applications with C#, VB.NET, or F# and XAML, powered by WebAssembly and .NET. It implements a large subset of the WPF API so a single codebase can target web, Android, iOS, Windows, macOS, and Linux, and it is designed to ease migration from legacy WPF, Silverlight, and LightSwitch apps.

## Use cases
- migrate a legacy Silverlight app to modern browsers without plugins
- port a WPF desktop application to the web
- build a cross-platform app in C# and XAML with one codebase
- run XAML UI in the browser via WebAssembly
- modernize a LightSwitch or Windows Forms application
- reuse existing WPF MVVM code on mobile and web

## When to choose
- you have existing WPF, Silverlight, or LightSwitch code and want to preserve it
- your team knows XAML and .NET and wants to avoid learning JavaScript frameworks
- you need one codebase targeting web, desktop, and mobile
- you want DOM-based rendering for accessibility, SEO, and text selection

## When to avoid
- you are starting a greenfield web app and prefer mainstream JS/TS ecosystems
- you need pixel-perfect custom rendering rather than HTML DOM output
- you rely on WPF APIs outside the subset OpenSilver implements
- you need a fully community-driven project without commercial backing

## Facets
- artifact type: framework
- maturity: active
- function: frontend-framework, ui-components, wasm, templating, state-management
- domain: web-development, frontend, cross-platform, mobile-development, desktop-applications, developer-tools
- platform: browser, wasm, cross-platform, windows, dotnet
- tags: xaml, wpf, silverlight, maui-hybrid, blazor, mvvm, dotnet, csharp, vbnet, fsharp, migration, photino, web-server, macos, linux, android, ios

## Member repositories
- OpenSilver/OpenSilver (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:09.948551+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T05:04:22.146639+00:00, confidence not recorded.
  - readme: https://github.com/OpenSilver/OpenSilver (fetched 2026-08-28T04:04:09.948551+00:00, sha 78030b5ab100)
  - homepage: https://opensilver.net (fetched 2026-08-29T12:16:47.878630+00:00, sha 976262d9ca5d)
  - site_page: https://doc.opensilver.net/documentation/general/overview.html (fetched 2026-08-29T12:16:47.888031+00:00, sha 0390c2eb31c7)
  - site_page: https://doc.opensilver.net/documentation/general/getting-started-tour.html (fetched 2026-08-29T12:16:47.890337+00:00, sha 59a62c73de2e)
  - site_page: https://opensilver.net/migration-service (fetched 2026-08-29T12:16:47.892261+00:00, sha 10fc863405ec)
- Data as of 2026-08-30T08:39:29.467469+00:00.