.NET Multi-platform App UI (.NET MAUI) is a cross-platform framework for creating native mobile and desktop apps with C# and eXtensible Application Markup Language (XAML). Using .NET MAUI, you can develop apps running on Android, iOS, macOS, and Windows from a single shared codebase.This book guides readers through the fundamentals of .NET MAUI cross-platform application development. It begins by exploring the concept of cross-platform development and introduces .NET MAUI, highlighting its evolution from Xamarin.Forms. The book then covers essential topics such as setting up the development environment, learning C# programming fundamentals, and mastering XAML for defining the user interface, including data binding. Through a series of practical projects, including a Color Picker, Tip Calculator, BMI Calculator, Unit Converter, and Weather App, readers gain hands-on experience in applying .NET MAUI concepts to build real-world mobile applications.The readers will gain a solid foundation in developing cross-platform applications using .NET MAUI. They will gain enough knowledge and skills to build simple applications for Windows, macOS, Android, and iOS.