The newest version of Microsoft. NET Framework. This package installs the. NET Framework and its associated files required to run applications developed to target the runtime. NET Framework.

. NET is a proprietary technology from Microsoft. Nevertheless, after the conclusion of an agreement with Novell, Mono technology has been recognized as a realization. NET on a Unix-like systems (GNU / Linux, Mac OS X). However, the agreement related to Novell customers, and Novell, as technologies ASP.NET, ADO.NET and Windows.Forms not been standardized by ECMA / ISO and use them in Mono is threatened by claims from Microsoft (claims are only possible in countries where there are patents on software). Mono provides an implementation of ASP.NET, ADO.NET and Windows.Forms, but at the same time encourages circumvent these API.

Development environment. NET-applications:

Microsoft Visual Studio (C #, Visual Basic. NET, Managed C + +),
SharpDevelop,
MonoDevelop,
Eclipse,
Borland Developer Studio (Delphi for. NET, C #),
PascalABC.NET etc.

Applications can also be developed in a text editor and use the console compiler.

Such technologies Java, development environment. NET generates byte code for execution by the virtual machine. The input language of this machine in. NET is called MSIL (Microsoft Intermediate Language), or CIL (Common Intermediate Language, a later version), or just IL. The use of bytecode allows us to obtain cross-platform at the compiled project (in terms of. NET: assembly), and not only at the level of the source text, such as in C. Before starting the assembly in the runtime CLR byte code is converted into a built environment JIT compiler (just in time, compiled on the fly) into machine code of the target processor. There is also a possibility to compile the assembly into native (native) code for the selected platform using came with. NET Framework utilities NGen.exe.

It should be noted that one of the first JIT-compiler for Java has also been developed by Microsoft. Modern technology of dynamic compilation can achieve performance levels similar to traditional "static" compilers (eg, C + +), and the question of speed often depends on the quality of a compiler.