VBScript (short for Visual Basic Scripting Edition) is
an Active Scripting language developed by Microsoft. The
language's syntax reflects its history as a limited variation
of Microsoft's Visual Basic programming language.
VBScript is installed by default in every desktop release
of Microsoft Windows since Windows 98,[1] and may or may
not be included with Windows CE depending on the configuration
and purpose of the device it is running on. It initially
gained support from Windows administrators seeking an automation
tool more powerful than the batch language first developed
in the late 1970s.
A VBScript script must be executed within a host environment,
of which there are several provided on a standard install
of Microsoft Windows (Windows Script Host, Internet Explorer).
Additionally, The VBScript hosting environment is embeddable
in other programs, through technologies such as the Microsoft
Script control (msscript.ocx).
VBScript began as part of the Microsoft Windows Script
Technologies, which were targeted at web developers initially
and were launched in 1996. During a period of just over
two years, the VBScript and JScript languages advanced from
version 1.0 to 2.0 (the latter was later renamed 5.0) and
over that time system administrators noticed it and began
using it. In version 5.0, the functionality of VBScript
was increased with new features such as regular expressions,
classes, the With statement,[2] Eval/Execute/ExecuteGlobal
functions to evaluate and execute script commands built
during the execution of another script, a function-pointer
system via GetRef(), and Distributed COM (DCOM) support.
In 5.5, "Submatches"[3] were added to the regular
expression class in VBScript to finally allow VBScript script
authors to capture the text within the expression's groups.
That capability before was only possible through the JScript
member of the Microsoft ActiveX Scripting family.
As of 2008, no new functionality will be added to the VBScript
language, which has been superseded by Windows PowerShell.
However, it will continue to be shipped with future releases
of Microsoft Windows, as will other components of the ActiveX
Scripting Family (such as JScript). Additionally, support
will continue due to the amount of code written in it and
because it is still considered a useful tool for some tasks.
The language engine is currently being maintained by Microsoft's
Sustaining Engineering Team, which is responsible for bug
fixes and security enhancements.
When employed in Microsoft Internet Explorer, VBScript is
similar in function to JavaScript, as a language to write
functions that are embedded in or included from HTML pages
and interact with the Document Object Model (DOM) of the
page, to perform tasks not possible in HTML alone. Other
web browsers such as Firefox, and Opera do not have built-in
support for VBScript. This means that where client-side
script is required on a web site, developers almost always
use JavaScript for cross-browser compatibility.
Besides client-side web development, VBScript is used for
server-side processing of web pages, most notably with Microsoft
Active Server Pages (ASP). The ASP engine and type library,
asp.dll, invokes vbscript.dll to run VBScript scripts. VBScript
that is embedded in an ASP page is contained within <%
and %> context switches. The following example of an
ASP page with VBScript displays the current time in 24-hour
format (Note that an '=' sign occurring after a context
switch (<%) is short-hand for a call to Write() method
of the Response object).