Prism
Prism is a framework for building loosely coupled, maintainable, and testable XAML applications in WPF, Xamarin Forms, and Uno Platform. It provides guidance and tools to implement design patterns like MVVM (Model-View-ViewModel), dependency injection, and modularity. Developed by Microsoft Patterns & Practices, it helps developers create scalable and well-structured desktop and mobile applications.
Developers should learn Prism when building complex XAML-based applications that require separation of concerns, testability, and maintainability, such as enterprise desktop apps or cross-platform mobile apps. It is particularly useful for scenarios involving modular architecture, navigation management, and event aggregation, reducing boilerplate code and enforcing best practices in WPF and Xamarin development.