.NET framework

language, tool, library A software development and execution

environment designed by Microsoft as a direct competitor to

Java. .NET framework should not be confused with

Microsoft's past labeling of a line of products as ".NET".

.NET simplifies interoperability between languages and

machines on Microsoft Windows especially, although not

specifically, for web based services. Essentially the .NET

framework 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 .NET

applications such as the security model, type system and .NET

classes (c.f. Java classes). The CTS is the range of all

types that .NET understands although it is not necessarily the

case that a .NET program will understand all of these types.

The CLS however is a subset of the CTS which all .NET

languages must support: any two .NET languages can

interoperate via. the CLS.

All .NET languages are at some stage compiled into the IL, a

byte-code like language. However unlike a standard Java run

time environment, the IL is converted to machine code either

upon installation of the software or at run time by a justin time compiler (JIT). The IL is not interpretted.

.NET's main weakness is that Microsoft have ignored the Unix

and mainframe environments, effectively ruling .NET out of

use in many enterprise environments. However there is

Mono - an open source .NET framework for Unix}.

.NET was based on research by Steven Lucco on a product called

OmniVM, sold by Colusa software. Attracted to OmniVM

since VB and C/C++ environments were already available,

Microsoft bought Colusa in 1996. Microsoft provides .NET

compilers for C#, C++, VB, and Jscript.

(2003-09-24)