You can build native mobile and desktop apps using C# and XAML using the .NET Multi-platform App UI (.NET MAUI), a Cross-platform framework.
.NET MAUI is an open-source successor to Xamarin.
The .NET platform (pronounced as "dot net") is a free and open-source, managed computer software framework for Windows, Linux, and macOS operating systems. The project is mainly developed by Microsoft employees by way of the .NET Foundation and is released under an MIT License.
New versions of the .NET platform are released annually, typically in November. The most recent version of .NET is .NET 9, released in November 2024, while the current long-term support (LTS) version is .NET 8, released in November 2023 and scheduled to receive updates until November 2026.