A comprehensive command line interface and scripting language for Windows. Introduced in 2006, PowerShell is a major upgrade from the Windows command line, which uses DOS commands (see command line). Although PowerShell supports common programming structures such as "if-then-else" and "while," it is generally less complicated than Microsoft's VBScript and JScript languages, and less code is often required (see Windows Script Host). The software used to develop PowerShell applications is the PowerShell Integrated Scripting Environment (PowerShell ISE). A Lot of Unix; a Little DOS Unix commands allow extensive manipulation of data via commands and scripts, and this capability has been available to Unix, Linux and Mac OS X users for years. When PowerShell came out, Windows programmers no longer had a reason to be envious, because PowerShell rivals the Unix command line and integrates it with Windows commands. Low-Level Access and Commandlets (Cmdlets) PowerShell uses the .NET environment and enables administrators to get to the heart of OS management, such as listing and stopping active processes. PowerShell scripts can access the class libraries in the .NET Framework, Component Object Model (COM) and Windows Management Instrumentation (WMI). The more than 125 PowerShell commands, such as list, copy, move and rename, are called "commandlets" or "cmdlets" for short. Script files use .PS# extensions, such as .PS1 for PowerShell Version 1. See .NET Framework, COM, WMI and command line.