prismlibrary/prism

Prism is a C# framework for building desktop and mobile applications with a clean, maintainable structure. It targets several UI platforms: WPF for traditional Windows desktop apps, Avalonia for cross-platform desktop, MAUI for iOS and Android, Uno Platform for cross-platform apps including web and desktop, and WinUI for modern Windows apps. The framework's core code is shared across all of these via a common library, while each platform gets its own adapter package. The main patterns Prism provides are MVVM, dependency injection, commands, and an event aggregator. MVVM (Model-View-ViewModel) is an approach that keeps the user interface and the underlying data logic separate so they can be developed and tested independently. Dependency injection is a technique that makes it easier to swap out components in tests and production, because each part of the code declares what it needs rather than creating its own dependencies. Commands give a clean way to connect button clicks and other actions to business logic without tying the UI tightly to any specific implementation. The event aggregator lets different parts of an application communicate without holding direct references to each other, a pattern sometimes described as loosely coupled design. Prism is available as a set of NuGet packages (the standard package system for .NET). Version 9.0 introduced dual licensing: a free community license covers most individual and open source uses, while a commercial license is required for larger organizations. A higher-tier commercial license also provides access to additional support libraries and a private support channel. Documentation is maintained in a separate repository and available online at the project's website.