Windows UI Library (WinUI codenamed "Jupiter", and also known as UWP XAML and WinRT XAML) is a

user interface In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine f ...

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

that is part of the

Windows Runtime Windows Runtime (WinRT) is a platform-agnostic component and application architecture first introduced in Windows 8 and Windows Server 2012 in 2012. It is implemented in C++ and officially supports development in C++ (via C++/WinRT, C++/CX or ...

programming model A programming model is an execution model coupled to an API or a particular pattern of code. In this style, there are actually two execution models in play: the execution model of the base programming language and the execution model of the pro ...

that forms the backbone of

Universal Windows Platform apps Universal Windows Platform (UWP) apps (formerly Windows Store apps and Metro-style apps) are applications that can be used across all compatible Microsoft Windows devices, including personal computers (PCs), tablets, smartphones, Xbox One, M ...

(formerly known as ''

Metro Metro, short for metropolitan, may refer to: Geography * Metro (city), a city in Indonesia * A metropolitan area, the populated region including and surrounding an urban center Public transport * Rapid transit, a passenger railway in an urban ...

-style'' or ''Immersive'') for the

Windows 8 Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on August 1, 2012; it was subsequently made available for download via MSDN and TechNet on August 15, 2012, and later to ...

, Windows 8.1,

Windows 10 Windows 10 is a major release of Microsoft's Windows NT operating system. It is the direct successor to Windows 8.1, which was released nearly two years earlier. It was released to manufacturing on July 15, 2015, and later to retail on ...

and

Windows Phone 8.1 Windows Phone 8.1 is the discontinued third generation of Microsoft's Windows Phone mobile operating system, succeeding Windows Phone 8. Rolled out at Microsoft's Build Conference in San Francisco, California, on April 2, 2014, it was released ...

operating systems. It enables declaring user interfaces using

Extensible Application Markup Language Extensible Application Markup Language (XAML ) is a declarative XML-based language that Microsoft developed for initializing structured values and objects. It is available under Microsoft's Open Specification Promise. XAML is used extensively ...

(XAML) technology. WinUI is one of the multiple UI frameworks provided built-in for the Windows Runtime; the others being

HTML5 HTML5 is a markup language used for structuring and presenting content on the World Wide Web. It is the fifth and final major HTML version that is a World Wide Web Consortium (W3C) recommendation. The current specification is known as the HT ...

(e.g., via WinJS) and

DirectX Microsoft DirectX is a collection of application programming interfaces (APIs) for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. Originally, the names of these APIs all began with "Direc ...

. WinUI 3 decouples WinRT XAML from the operating system as a separate package to be updated quickly and make new features work on older versions of Windows. It is part of

Windows App SDK Windows App SDK (formerly known as Project Reunion) is a software development kit (SDK) from Microsoft that targets the development of Windows API, native desktop applications on Windows 11 and Windows 10 back to version 1809. Windows App SDK doe ...

(codenamed "Project Reunion"), a Microsoft effort to reconcile the Windows desktop (Win32) and the UWP low IL app model.

Windows Phone

Up to Windows Phone 8.0 WinRT XAML was not supported and XAML applications were based on

Silverlight Microsoft Silverlight is a discontinued application framework designed for writing and running rich web applications, similar to Adobe's runtime, Adobe Flash. A plugin for Silverlight is still available for a very small number of browsers. Wh ...

XAML and deployed in XAP format. In

WinRT XAML is available along with improved Windows Runtime support. This convergence between platforms enable

Universal app Universal Windows Platform (UWP) apps (formerly Windows Store apps and Metro-style apps) are applications that can be used across all compatible Microsoft Windows devices, including personal computers (PCs), tablets, smartphones, Xbox One, ...

s that can target both Windows 8.1 and Windows Phone 8.1 while sharing most of the code, including user interface. The

is still capable of running

XAML apps and new features and API were also added to this too (called

8.1)

Related technologies

WinUI is related to

Windows Presentation Foundation Windows Presentation Foundation (WPF) is a free and open-source graphical subsystem (similar to WinForms) originally developed by Microsoft for rendering user interfaces in Windows-based applications. WPF, previously known as "Avalon", was init ...

(WPF) and

(WPF/E)—similar XAML-based UI frameworks used for desktop applications and portable applications respectively. WinUI uses a lot of the same names for its APIs as both of these older technologies—especially Silverlight, but its use is limited to the Windows (specifically Windows 8 and later) as with WPF. The major difference is that WPF and Silverlight are written in C# and require using

.NET language The domain name net is a generic top-level domain (gTLD) used in the Domain Name System of the Internet. The name is derived from the word ''network'', indicating it was originally intended for organizations involved in networking technologies ...

s such as C# or

Visual Basic Visual Basic is a name for a family of programming languages from Microsoft. It may refer to: * Visual Basic .NET (now simply referred to as "Visual Basic"), the current version of Visual Basic launched in 2002 which runs on .NET * Visual Basic (c ...

, while WinRT XAML is part of the Windows Runtime, written in C++ and available to

native code In computer programming, machine code is any low-level programming language, consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). Each instruction causes the CPU to perform a ver ...

, and has tools for development, with

C++/CX C++/CX ''(C++ component extensions)'' is a language projection for Microsoft's Windows Runtime platform. It takes the form of a language extension for C++ compilers, and it enables C++ programmers to write programs that call Windows Runtime (WinRT) ...

C++/WinRT C++/WinRT is a C++ library for Microsoft's Windows Runtime platform, designed to provide access to modern Windows APIs. C++/WinRT is provided as a standard C++17 header file library, unlike C++/CX, which is an extension to C++ and requires a re ...

References

External links

* * *
Microsoft.UI.Xaml namespace documentation
on

Microsoft Docs Microsoft Docs is the library of technical documentation for end users, developers, and IT professionals who work with Microsoft products. The Microsoft Docs website provides technical specifications, conceptual articles, tutorials, guides, API ...

Windows.UI.Xaml namespace documentation
on

Channel 9 - XAML presentations from the 2011 Build conference
* {{Microsoft FOSS Microsoft application programming interfaces Free and open-source software Free software programmed in C++ Free software programmed in C Sharp Microsoft development tools Microsoft free software Computer-related introductions in 2011 Software using the MIT license Widget toolkits Windows-only free software

Windows Phone

Related technologies

See also

References

External links