.NET

.NET is the free, open-source developer platform that builds high-performance, cross-platform applications (web, mobile, desktop) using C#.

This is the unified, modern platform for all your application development: Forget the old Framework; we're operating on .NET (e.g., .NET 8 LTS). It’s a cross-platform engine, running natively on Windows, Linux, and macOS. Developers leverage C# (the primary language) to build diverse application types: ASP.NET Core handles high-scale cloud services and web APIs; Blazor enables full-stack C# web UI; and .NET MAUI targets native mobile and desktop apps from a single codebase (iOS, Android, Windows). The platform is fast, reliable, and backed by Microsoft and the .NET Foundation, with over 300,000 packages available through NuGet.

https://dotnet.microsoft.com