Mono is a platform for running and developing applications based on the ECMA/ISO Standards. Mono is an open source effort led by Xamarin. Mono provides a complete CLR (Common Language Runtime) including compiler and runtime, which can produce and execute CIL (Common Intermediate Language) bytecode (aka assemblies), and a class library.

This package contains various development tools and pulls in the default development stack for Mono (which is 4.0 currently).