What Is the Common Language Infrastructure?

The common language infrastructure (CLI) is a set of international technical standards promoting computer programming language interoperability. CLI also allows many high-level languages to develop applications that are independent of platforms and architectures. There are more than 30 programming languages grouped for this purpose and making use of four divisions of common language programming specifications to become CLI compliant.

Making use of what is called a common type system (CTS), using a set of data types and operations and metadata information on programming structures allows cross-language code writing. The CLI compiles languages into a common intermediate language (CIL), and from CIL, communicates the application aspects to assembly machine language, which addresses the hardware. Additionally, there are common language specifications (CLS), which are a base rules set for use by any language seeking interoperation, and a virtual execution system (VES) for the loading, execution, and generation of run codes for all CLI-compliant programs.

Most CLI-compliant languages compile directly to the CIL by use of the common language runtime (CLR). After being compiled and cached, a just-in-time compiler then appropriates machine code from the existing architecture. The assembly machine code construction can also be constructed ahead of the CLR with an ahead-of-time compiler.

For CLI-compliant languages to take advantage of object specificity, common language infrastructure specifies that objects only need expose the features they hold in common with the other CLI-compliant languages when being called. Components of code developed to use only data types accepted in the CTS are said to be CLI compliant and accessible to all the other CLI-compliant languages. Additionally, any construct of a language that cannot be verified quickly by the type safety of the code is excluded from the CLS, so that only verifiable codes can be said to be CLS compliant.

Some programming features are common to both compilers and developers and others are available to compilers only. The list is lengthy and full of helpful features. A feature available only to compilers is: keywords that supply referencing identifiers and that can override virtual methods with names that are keywords. A feature available to both compilers and developers includes: modifier features that say that a property as well as its assessors must be all “static,” must all be “virtual,” must all be “instance.”

Implementation programs are for desktops, servers, mobile devices, and game consoles. Computer vision enhancement programs and low-level virtual machine toolkits are also developed from common language infrastructure–compliant languages. The common language infrastructure runtimes allocate system resources and call peripheral devices efficiently, though they are platform independent.