Can C# applications be run and used on Linux operating system?

Yes, C# applications can be run and used on Linux operating systems. This is made possible by the cross-platform runtime environment .NET Core (now .NET 5/6/7 and above), which supports Linux, Windows, and macOS.

This allows developing and running C# applications outside of Windows, which is especially convenient for server applications, microservices, and containerization.

Example of running an application:

1. Install the .NET SDK for Linux from the official website.
2. Create and build the application:

dotnet new console -o MyApp
cd MyApp
dotnet run

Thus, C# has become a fully cross-platform language thanks to the development of .NET Core and subsequent versions.