Common Intermediate Language

Common Intermediate Language (CIL), formerly called Microsoft Intermediate Language (MSIL), is the lowest-level human-readable programming language defined by the Common Language Infrastructure (CLI) specification and is used by the .NET Framework, .NET Core, 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. Common Intermediate Language (CIL), formerly called Microsoft Intermediate Language (MSIL), is the lowest-level human-readable programming language defined by the Common Language Infrastructure (CLI) specification and is used by the .NET Framework, .NET Core, 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. CIL was originally known as Microsoft Intermediate Language (MSIL) during the beta releases of the .NET languages. Due to standardization of C# and the Common Language Infrastructure, the bytecode is now officially known as CIL. During compilation of CLI programming languages, the source code is translated into CIL code rather than into platform- or processor-specific object code. CIL is a CPU- and platform-independent instruction set that can be executed in any environment supporting the Common Language Infrastructure, such as the .NET runtime on Windows, or the cross-platform Mono runtime. In theory, this eliminates the need to distribute different executable files for different platforms and CPU types. CIL code is verified for safety during runtime, providing better security and reliability than natively compiled executable files.