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 fro ...

API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...

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 ...

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 p ...

that forms the backbone of

Universal Windows Platform apps Universal Windows Platform (UWP) apps (formerly named Windows Store apps, Metro-style apps and Modern apps) are applications that can be used across all compatible Microsoft Windows devices. They are primarily purchased and downloaded via the ...

(formerly known as ''

Metro Metro may refer to: Geography * Metro City (Indonesia), 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 area with high ...

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

Windows 8 Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on August 1, 2012, made available for download via Microsoft ...

Windows 8.1 Windows 8.1 is a release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on August 27, 2013, and broadly released for retail sale on October 17, 2013, about a year after the retail release of its pr ...

Windows 10 Windows 10 is a major release of Microsoft's Windows NT operating system. The successor to Windows 8.1, it was Software release cycle#Release to manufacturing (RTM), released to manufacturing on July 15, 2015, and later to retail on July 2 ...

and Windows Phone 8.1 operating systems. It enables declaring user interfaces using

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

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

HTML5 HTML5 (Hypertext Markup Language 5) is a markup language used for structuring and presenting hypertext documents on the World Wide Web. It was the fifth and final major HTML version that is now a retired World Wide Web Consortium (W3C) recommend ...

(e.g., via

WinJS The Windows Library for JavaScript (abbreviated as WinJS) is an open-source JavaScript library developed by Microsoft. It has been designed with the primary goal of easing development of Windows Store apps for Windows 8 and Windows 10, as well ...

) 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 "Direct" ...

. WinUI 2 is an extension library for UWP XAML containing controls and styling that match the Windows 11 design language. It is shipped through NuGet and is distinct from the UWP XAML framework, which provides the actual rendering engine; though, they may be treated as synonyms. 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 provides a unified set of APIs and components that can be used to develop desktop applications for both Windows 11 and Windows 10 version ...

(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 internet applications, similar to Adobe's runtime, Adobe Flash. While early versions of Silverlight focused on streaming media, later version ...

XAML and deployed in XAP format. In Windows Phone 8.1 WinRT XAML is available along with improved Windows Runtime support. This convergence between platforms enable

Universal app Universal Windows Platform (UWP) apps (formerly named Windows Store apps, Metro-style apps and Modern apps) are applications that can be used across all compatible Microsoft Windows devices. They are primarily purchased and downloaded via the ...

s that can target both Windows 8.1 and Windows Phone 8.1 while sharing most of the code, including user interface. The Windows Phone 8.1 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 user interface framework for Windows-based desktop applications. WPF applications are based in .NET, and are primarily developed using C# and XAML. Originally developed by Microso ...

(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 languages 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), the current version of Visual Basic launched in 2002 which runs on .NET * Visual Basic (classic), the original Visual Basic suppo ...

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

native code In computer programming, machine code is computer program, computer code consisting of machine language instruction set architecture, instructions, which are used to control a computer's central processing unit (CPU). For conventional binary ...

, 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 API, Windows APIs. C++/WinRT is provided as a standard C++17 header file library, unlike C++/CX, which is an extension to C++ and req ...

References

External links

*
WinUI
on

Microsoft Learn Microsoft Learn is a library of technical documentation and training for end users, developers, and IT professionals who work with Microsoft products. Microsoft Learn was introduced in September 2018. In 2022, Microsoft Docs, the technical documen ...

** *
Windows.UI.Xaml namespace documentation
on

XAML presentations
from 2011

Microsoft Build Microsoft Build (often stylised as ) is an annual Business conference, conference event held by Microsoft, aimed at Software engineering, software engineers and web developers using Windows, Microsoft Azure and other Microsoft technologies. Fi ...

conference on

(originally on Channel 9) * {{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 2011 software Software using the MIT license Widget toolkits Windows-only free software

Windows Phone

Related technologies

See also

References

External links