The Howdy Glossary

Common Intermediate Language (CIL) acts as an intermediary between source code and machine code, generated by compilers for .NET languages like C# and Visual Basic.NET. Within the .NET Framework, the Common Language Runtime (CLR) executes these CIL instructions, which are then translated into platform-specific machine code by the Just-In-Time (JIT) compiler. This facilitates cross-platform execution of applications without necessitating recompilation for different systems.

Microsoft developed CIL, originally known as Microsoft Intermediate Language (MSIL), to support the .NET Framework's goal of platform-agnostic application execution. By compiling source code from various .NET languages into CIL instructions, which are later translated to native machine code at runtime, applications can run on multiple platforms. This capability not only ensures portability and interoperability but also promotes flexibility in software development by allowing different languages to target a common runtime environment.

CIL offers several unique features that make it a vital component of the .NET ecosystem. Its platform independence allows applications to be executed across different systems without requiring re-compilation. Additionally, it supports multiple .NET languages targeting the same runtime environment, enhancing code reuse and interoperability. The JIT compilation process ensures performance optimization by dynamically translating CIL instructions into native machine code during execution. These attributes collectively underscore CIL's role in enabling cross-language compatibility, fostering platform neutrality, and streamlining dynamic compilation within the development of robust .NET applications.