Mono is a command line tool that serves as an implementation of the .NET Framework. It allows developers to run applications developed on the .NET Framework on various platforms, such as Unix, Linux, macOS, and Windows. Mono provides a runtime engine, compiler, and an extensive set of libraries, enabling the execution of C#, F#, and Visual Basic .NET applications on non-Windows operating systems. It offers cross-platform compatibility and facilitates the development of applications that can run on multiple target platforms without major modifications. The tool supports a wide range of development environments and IDEs, including Visual Studio Code, JetBrains Rider, and MonoDevelop. Mono is an open-source project and is actively maintained by the .NET Foundation, ensuring regular updates, bug fixes, and new feature additions. It plays a significant role in enabling organizations and developers to leverage the power of the .NET framework in heterogeneous environments.