XAML Browser Applications (XBAP, pronounced "ex-bap") are
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 ...
(.xbap) applications that were intended to run inside a
web browser
A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...
such as
Firefox
Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements curr ...
or
Internet Explorer
Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated as IE or MSIE) is a deprecation, retired series of graphical user interface, graphical web browsers developed by Microsoft that were u ...
through the
NPAPI interface. Due to NPAPI being phased out in recent years, and from lack of support, there are currently no browsers that support XBAP applications.
Hosted applications run in a partial trust
sandbox environment and are not given full access to the computer's resources like opening a new network connection or saving a file to the computer disk and not all
WPF functionality is available. The hosted environment is intended to protect the computer from
malicious applications; however it can also run in full trust mode by the client changing the permission. Starting an XBAP from an
HTML
Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...
page was seamless (with no security or installation prompt). Although one perceived the application running in the browser, it actually ran in an out-of-process executable (PresentationHost.exe) managed by a
virtual machine
In computing, a virtual machine (VM) is the virtualization or emulator, emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve ...
.
XBAP limitations
XBAP applications have certain restrictions on what
.NET
The .NET platform (pronounced as "''dot net"'') is a free and open-source, managed code, managed computer software framework for Microsoft Windows, Windows, Linux, and macOS operating systems. The project is mainly developed by Microsoft emplo ...
features they can use. Since they run in partial trust, they are restricted to the same set of permission granted to any InternetZone application. Nearly all standard WPF functionality, however, around 99%, is available to an XBAP application. Therefore, most of the WPF
UI features are available.
Starting in February 2009, XBAP applications no longer function when run from the Internet. Attempting to run the XBAP will cause the browser to present a generic error message. An option exists in Internet Explorer 9 that can be used to allow the applications to run, but this must be done with care as it increases the potential
attack surface
The attack surface of a software environment is the sum of the different points (for " attack vectors") where an unauthorized user (the "attacker") can try to enter data to, extract data, control a device or critical software in an environment. Ke ...
- and there have been security vulnerabilities in XBAP.
Permitted
*2D drawing
*3D
*Animation
*Audio
Not permitted
*Access to OS
drag-and-drop
In computer graphical user interfaces, drag and drop is a pointing device gesture in which the user selects a virtual object by "grabbing" it and dragging it to a different location or onto another virtual object. In general, it can be used to ...
*Bitmap effects (these are deprecated in .NET 3.5 SP1)
*Direct database communication (unless the application is fully trusted)
*Interoperability with Windows controls or
ActiveX
ActiveX is a deprecated software framework created by Microsoft that adapts its earlier Component Object Model (COM) and Object Linking and Embedding (OLE) technologies for content downloaded from a network, particularly from the World Wide W ...
controls
*Most standard dialogs
*Shader effects
*Stand-alone Windows
See also
*
ClickOnce
ClickOnce is a component of Microsoft .NET Framework 2.0 and later, and supports deploying applications made with Windows Forms or Windows Presentation Foundation. It is similar to Java Web Start for the Java Platform or Zero Install for Linu ...
*
Extensible Application Markup Language (XAML)
*
Google Native Client
Google Native Client (NaCl) is a discontinued sandboxing technology for running either a subset of Intel x86, ARM, or MIPS native code, or a portable executable, in a sandbox. It allows safely running native code from a web browser, independ ...
(NaCl)
*
HTML Application (HTA)
*
Microsoft Silverlight
Microsoft Silverlight is a discontinued application framework designed for writing and running rich internet applications, similar to Adobe Inc., Adobe's Run time environment, runtime, Adobe Flash. While early versions of Silverlight focused on ...
*
WebAssembly
WebAssembly (Wasm) defines a portable binary-code format and a corresponding text format for executable programs as well as software interfaces for facilitating communication between such programs and their host environment.
The main goal of ...
*
Windows UI Library
Windows UI Library (WinUI codenamed "Jupiter", and also known as UWP XAML and WinRT XAML) is a user interface API that is part of the Windows Runtime programming model that forms the backbone of Universal Windows Platform apps (formerly known as ...
(WinUI or WinRT XAML)
*
XAP (file format)
XAP is the file format used to distribute and install application software and middleware onto Microsoft's Windows Phone 7/8/8.1/10 operating system, and is the file format for Silverlight applications. Beginning with Windows Phone 8.1, XAP was ...
*
Java Web Start
In computing, Java Web Start (also known as JavaWS, javaws or JAWS) is a deprecated framework developed by Sun Microsystems (now Oracle) that allows users to start application software for the Java Platform directly from the Internet using a web b ...
References
External links
Windows Presentation Foundation Security Sandbox
{{Archive formats
.NET Framework terminology
Microsoft application programming interfaces