Common Language Specification &

Common Language Specification

One of the obvious themes of .NET is unification and interoperability between various programming languages. In order to achieve this; certain rules must be laid and all the languages must follow these rules. CLS is the collection of the rules and constraints that every language (that seeks to achieve .NET compatibility) must follow.

The Common Language Specification is a set of basic language features (constructs and constraints) that serves as a guide for library writers and compiler writers. It allows libraries to be fully usable from any language supporting the CLS, and for those languages to integrate with each other. The Common Language Specification is a subset of the common type system. The CLS is actually a set of restrictions on the CTS. The CLS defines not only the types allowed in external calls, but the rules for using them, depending on the goal of the user.

The Common Language Specification describes a common level of language functionality. The CLS is a set of rules that a language compiler must follow to create .NET applications that run in the CLR. Anyone who wants to write a .NET compliant compiler needs simply to follow these rules and that's it.

Base Class Library

The .NET Framework base class library contains the base classes that provide many of the services and objects you need when writing your applications. The class library is organized into namespaces. The .NET Framework Class Library (FCL) is a set of managed classes that provide access to system services. File input/output, sockets, database access, remoting, and XML are just some of the services available in the FCL. Importantly, all the .NET languages rely on the same managed classes for the same services. This is one of the reasons that, once you have learned any .NET language, you have learned 40 percent of every other managed language. The same classes, methods, parameters, and types are used for system services regardless of the language. This is one of the most important contributions of FCL.