Initially released as an add-on to Internet Information Services (IIS) via the Windows NT 4.0 Option Pack, it was subsequently included as a free component of Windows Server (since the initial release of Windows 2000 Server).
ASP 2.0 provided six built-in objects: Application, ASPError, Request, Response, Server, and Session. Session, for example, represents a cookie-based session that maintains the state of variables from page to page. The Active Scripting engine's support of the Component Object Model (COM) enables ASP websites to access functionality in compiled libraries such as DLLs.
ASP supports multiple programming languages, including VBScript, but there are other options. An alternative Active Scripting engine can be selected with the @Language directive or the syntax. JScript (Microsoft's implementation of ECMAScript) is the other language that is built-in. PerlScript (a derivative of Perl) and others are available as third-party installable Active Scripting engines.