Active Scripting
Active Scripting (also known as ActiveX Scripting) is the technology used in Windows to implement component-based scripting support. It is based on ActiveX/COM and allows installation of additional scripting engines in the form of COM modules.
Initially Windows comes with VBScript and JScript engines preinstalled, but there are many free and commercial Active Scripting engines available. For example, one can add support for Perl scripting to Windows by installing ActivePerl engine, or HaskellScript engine for Haskell support.
Active Scripting is now being deprecated in favor of .NET, and no new versions of VBScript or JScript will be produced (the newer and slightly incompatible languages Visual Basic .NET and JScript .NET are marketed as replacement for them). However, .NET languages are available via Active Scripting, so even .NET-unaware applications can be scripted in .NET languages, given the .NET framework is installed.