.NET framework

(language, tool, library)A software development and executionenvironment designed by Microsoft as a direct competitor toJava. .NET framework should not be confused withMicrosoft's past labeling of a line of products as ".NET".

.NET simplifies interoperability between languages andmachines on Microsoft Windows especially, although notspecifically, for web based services. Essentially the .NETframework consists of the CLR (common language runtime), CTS(common type system), CLS (common language system), and IL(intermediate language).

The CLR consists of a number of resources provided to .NETapplications such as the security model, type system and .NETclasses (c.f. Java classes). The CTS is the range of alltypes that .NET understands although it is not necessarily thecase that a .NET program will understand all of these types.The CLS however is a subset of the CTS which all .NETlanguages must support: any two .NET languages caninteroperate via. the CLS.

All .NET languages are at some stage compiled into the IL, abyte-code like language. However unlike a standard Java runtime environment, the IL is converted to machine code eitherupon installation of the software or at run time by a just in time compiler (JIT). The IL is not interpretted.

.NET's main weakness is that Microsoft have ignored the Unixand mainframe environments, effectively ruling .NET out ofuse in many enterprise environments. However there isMono - an open source .NET framework for Unix}.

.NET was based on research by Steven Lucco on a product calledOmniVM, sold by Colusa software. Attracted to OmniVMsince VB and C/C++ environments were already available,Microsoft bought Colusa in 1996. Microsoft provides .NETcompilers for C#, C++, VB, and Jscript.

.NET Framework

An application software platform from Microsoft, introduced in 2002 and commonly called "dot net." The .NET platform was initially developed for Windows but has been ported to other operating systems (see Mono).

A Bytecode Language
Like Java, .NET is an intermediate bytecode language that requires a runtime interpreter in the computer to execute. .NET compilers generate Microsoft Intermediate Language (MSIL) that is executed by the .NET Common Language Runtime engine (see CLR). SOAP-based Web services and Microsoft's legacy Component Object Model (COM) are supported. See SOAP and COM.

Programming Languages
The primary .NET languages are C# (C Sharp), J# (J Sharp), Managed C++, JScript.NET and Visual Basic.NET. Non-Microsoft languages are supported in the European version of .NET (see CLI) as well as the cross platform version (see Mono). See C#, J#, CLI and .NET Framework Client Profile).

.NET Framework Interfaces

See WPF, Windows Communication Foundation, Windows Workflow Foundation and Windows CardSpace.