Extensible Application Markup Language

XAML originally stood for Extensible Avalon Markup Language, Avalon being the code-name for Windows Presentation Foundation (WPF). Before the end of .NET Framework 3.0 development, however, Microsoft adopted XAML for Workflow Foundation (WF). which may be inserted as a resource into a .NET Framework assembly. At run-time, the framework engine extracts the BAML file from assembly resources, parses it, and creates a corresponding WPF visual tree or workflow. In WF contexts, XAML describes potentially long-running declarative logic, such as those created by process modeling tools and rules systems. The serialization format for workflows was previously called XOML, to differentiate it from UI markup use of XAML, but now they are no longer distinguished. However, the file extension for files containing the workflow markup is still ".xoml". XAML uses a specific way to define look and feel called Templates; differing from Cascading Style Sheet syntax, it is closer to XBL. To create XAML files, one could use Microsoft Expression Blend, Microsoft Visual Studio, the hostable WF visual designer, or XAMLPad. ==Examples==

This Windows Presentation Foundation example shows the text "Hello, world!" in the top-level XAML container called Canvas. Hello, world! The schema (the part) may have to be changed to work on some computers. Using a schema that Microsoft recommends, the example can also be Hello, world! A crucial part of utilizing XAML to its full potential is making appropriate usage of binding, as well as creating custom user elements as required. Binding can be done as follows: ==Differences between versions of XAML==

There are three main Microsoft implementations of XAML: • Windows Presentation Foundation (WPF), first available with .NET Framework 3.0 • Silverlight 3 and 4, first available for Internet Explorer 6 and now deprecated • Windows UI Library (formerly UWP XAML and WinRT XAML), first shipped with Windows 8 and Windows Server 2012, but now available as a part of the Windows App SDK These versions have some differences in the parsing behavior. Additionally, the Silverlight 4 XAML parser is not 100% backward-compatible with Silverlight 3 files. Silverlight 3 XAML files may be rejected or parsed differently by the Silverlight 4 parser. Besides Microsoft implementations, there is also OpenSilver (formerly known as CSHTML5), a contemporary web technology implementation. == XAML applications in web browsers ==

Historically, XAML based applications could be run in some web browsers, such as Internet Explorer and Firefox. This could be achieved through XBAP files created from WPF applications, or via the Silverlight browser plugin. However, both these methods are now unsupported on all major browsers due to their reliance on the discontinued NPAPI browser plugin interface. ==Lock-in concerns==

In 2007, European Committee for Interoperable Systems (ECIS) – a coalition of mostly American software companies – accused Microsoft of attempting to hijack HTML and replace it with XAML, thus creating a vendor lock-in. Jeremy Reimer, writing for Ars Technica described this comment as "the most egregious error" and added that XAML is unlikely to ever replace HTML. ==See also==