Common Intermediate Language

Common Intermediate Language (CIL, pronounced either "sil" or "kil"), formerly called Microsoft Intermediate Language or MSIL, is the lowest-level human-readable programming language defined by the Common Language Infrastructure (CLI) specification and is used by the .NET Framework and Mono. Languages which target a CLI-compatible runtime environment compile to CIL, which is assembled into an object code that has a bytecode-style format. CIL is an object-oriented assembly language, and is entirely stack-based. Its bytecode is translated into native code or — most commonly — executed by a virtual machine.