C Sharp

For other uses, see C (disambiguation).

C# is a popular, general-purpose programming language developed for the Microsoft .NET Framework. C# is fully object-oriented and is under continuous active development by Microsoft. C# programs are fully portable across all recent Microsoft operating systems since Windows 2000/XP (and partially on Windows 98). As of 2008, C# is in release version 3.

C# programs consist of .exe or .dll files, each containing Common Intermediate Language (CIL) instructions, a manifest (table of contents), metadata, and (possibly) encapsulated resources such as images or audio.

C# is standardized by ECMA (the ECMA-334 standard) and by ISO/IEC (the ISO/IEC 23270 standard). Microsoft’s C# for the .NET Framework is a conforming implementation of both of these standards. To execute on Windows, C# programs require the installation of the .NET Framework Common Language Runtime (CLR), a virtual machine that hides operating system details. The CLR is available both for Windows client computers and Microsoft Web servers. An independent version of the Common Language Runtime (not developed by Microsoft) is available as a result of the open source Mono Project; it provides software to develop and run .NET applications on Linux, Solaris, Mac OS X, Windows, and Unix.

Many consider C# to be Microsoft's reaction to the popularity of the Java programming language and Java platform.

In C# 3.0, Microsoft has added the 'var' keyword, which allows type inference. For instance, one might declare: var fooString = "Hello, World!"; when in previous versions, one might have to write: string fooString = "Hello, World!";