Avalonia is a WPF-inspired cross-platform XAML-based UI framework providing a flexible styling system and supporting a wide range of OSs: Windows (.NET Framework, .NET Core), Linux (GTK), MacOS, Android and iOS.
<b>Avalonia is now in alpha.</b> This means that framework is now at a stage where you can have a play and hopefully create simple applications. There's still a lot missing, and you *will* find bugs, and the API *will* change, but this represents the first time where we've made it somewhat easy to have a play and experiment with the framework.
Avalonia [Visual Studio Extension](https://marketplace.visualstudio.com/items?itemName=AvaloniaTeam.AvaloniaforVisualStudio) contains project and control templates that will help you get started. After installing it, open "New Project" dialog in Visual Studio, choose "Avalonia" in "Visual C#" section, select "Avalonia .NET Core Application" and press OK (<ahref="http://avaloniaui.net/tutorial/images/add-dialogs.png">screenshot</a>). Now you can write code and markup that will work on multiple platforms!
Avalonia is delivered via <b>NuGet</b> package manager. You can find the packages here: ([stable(ish)](https://www.nuget.org/packages/Avalonia/), [nightly](https://github.com/AvaloniaUI/Avalonia/wiki/Using-nightly-build-feed))
As mentioned above, Avalonia is still in alpha and as such there's not much documentation yet. You can take a look at the [getting started page](http://avaloniaui.net/guides/quickstart) for an overview of how to get started but probably the best thing to do for now is to already know a little bit about WPF/Silverlight/UWP/XAML and ask questions in our [Gitter room](https://gitter.im/AvaloniaUI/Avalonia).
There's also a high-level [architecture document](http://avaloniaui.net/architecture/project-structure) that is currently a little bit out of date, and I've also started writing blog posts on Avalonia at http://grokys.github.io/.
