Developed by Microsoft, the Windows Presentation Foundation (or WPF) is a computer-software graphical subsystem for rendering user interfaces in Windows-based applications. WPF, previously known as "Avalon", was initially released as part of .NET Framework 3.0. Rather than relying on the older GDI subsystem, WPF uses DirectX. WPF attempts to provide a consistent programming model for building applications and separates the user interface from business logic. It resembles similar XML-oriented object models, such as those implemented in XUL and SVG.

WPF applications can also be deployed as standalone desktop programs, or hosted as an embedded object in a website. WPF aims to unify a number of common user interface elements, such as 2D/3D rendering, fixed and adaptive documents, typography, vector graphics, runtime animation, and pre-rendered media. These elements can then be linked and manipulated based on various events, user interactions, and data bindings.