# XAML.io v0.8 — Fact Sheet

**Embargoed until Monday, July 6, 2026 (8:00 a.m. ET / 2:00 p.m. CEST).**

**What it is:** XAML.io v0.8 adds **Migrate from WPF** — free, in-browser tools that bring an existing Windows Presentation Foundation (WPF) application to the web. Developers can analyze a compiled WPF app for web compatibility, import a WPF project and run it in the browser, or engage Userware for an end-to-end migration. Powered by OpenSilver, Userware's open-source framework that runs WPF-style C# and XAML on the web via WebAssembly, rendering XAML as real HTML DOM.

**The positioning, in one line:** migrate your WPF app to the web with minimal code changes — deliberately *not* an AI rewrite.

## Key facts

- **Proof point:** Family.Show, the advanced WPF reference app Vertigo built for Microsoft, migrated and running live in the browser, with **97% of the original code unchanged** (measured as a line-by-line diff of the C# and XAML files between the original and migrated codebases).
- **Footprint:** the migrated app, including the entire .NET runtime, is **8.1 MB compressed**, with **no browser plugin** to install. CDN-served, it loads in a few seconds and is then cached; runtime performance is smooth.
- **Reach:** runs on any device with a browser (desktop, tablet, phone); the same C#/XAML codebase can also ship as desktop and mobile apps.
- **No AI rewrite:** the original C# and XAML are preserved; only small, visible, reviewable changes are applied (compiler directives, XAML comments, in-IDE warnings), plus a runtime alert system that flags stubbed/disabled code without crashing the app.
- **Compatibility tooling:** ships **8 Roslyn analyzers and 16 automatic code fixes** today; WPF coverage in OpenSilver expands continually.
- **Privacy:** the whole flow (analyze, import, fix, run, export a Visual Studio solution) can run locally in the browser with no signup; source code is not sent to Userware's servers. Cloud save, sharing, and AI features are opt-in.
- **No lock-in:** download a standard Visual Studio solution at any time and continue in Visual Studio, VS Code, Rider, or another IDE.

## Pricing

- **Self-serve tools: 100% free**, no time limit or feature paywall. OpenSilver is open source (MIT).
- **Optional paid:** professional services and support for production migrations of any size; organizations can sponsor specific WPF features, which then ship to everyone in the open-source framework. That model funds the free tools.

## Honest status

- The Compatibility Analyzer is robust for apps of **any size**.
- In-browser source import is a **Technology Preview**, best suited to small to mid-size, self-contained projects today; larger apps still need some manual work.
- Third-party UI control suites are not yet supported in the self-serve tools and are handled within managed migrations.

## Availability

- Available now at https://xaml.io
- Technical write-up (live July 6): https://blog.xaml.io/post/migrate-wpf-to-the-web/
- Family.Show live demo: https://familyshow.xaml.io
- Family.Show source code: https://xaml.io/s/Samples/Source/FamilyShow
- Free migration assessment: https://opensilver.net/talk-to-expert/

## About Userware

Userware is the company behind OpenSilver, the open-source framework that runs C# and XAML in the browser via WebAssembly, and XAML.io, the free web-based .NET IDE built on it. For more than 13 years, Userware has migrated enterprise XAML applications (Silverlight, LightSwitch, and WPF) to modern platforms for organizations including DENSO, Tata Communications, Symcor, LiveData (healthcare), Repton (education), and many more across financial services, manufacturing, and the public sector. Userware is based in Paris, France.

## Media contact

Vasil Buraliev — Media Relations, Userware — vasil.buraliev@userware.dev
