JScript .NET

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JScript .NET is a .NET framework programming language developed by Microsoft as proprietary software.

The main differences between JScript and JScript .NET can be summarized as:

Firstly, JScript is a scripting language, and as such, programs (or more suggestively, scripts) can be executed with no need to compile the code before. This is not the case with the JScript .NET command-line interface compiler, since this next-generation version relies on the .NET Common Language Runtime (CLR) for execution, which requires that the code be compiled to Common Intermediate Language (CIL), formerly named Microsoft Intermediate Language (MSIL), code before it can be run. Nevertheless, JScript .NET still fully supports interpreting source code at runtime (e.g., via the Function constructor or the eval function) and indeed the interpreter can be exposed by custom applications hosting the JScript .NET engine via the VSA^[jargon] interfaces.

Secondly, JScript has a strong foundation in Microsoft's ActiveX and Component Object Model (COM) technologies, and relies mainly on ActiveX components to provide much of its function (including database access via ActiveX Data Objects (ADO), file handling, etc.), whereas JScript .NET uses the .NET framework to provide equivalent function. For backward-compatibility (or for where no .NET equivalent library exists), JScript .NET still provides full access to ActiveX objects via .NET and COM Interop using both the ActiveXObject constructor and the standard methods of the .NET Type class.

Although the .NET framework and languages such as C# and Visual Basic (.NET) have been adopted widely, JScript .NET has received little attention, from the media and developers. It is not supported in Microsoft's premier development tool, Visual Studio .NET. However, ASP.NET supports JScript .NET.