What VBScript Is and Where It Comes From
BASIC, an acronym for beginner’s all-purpose instruction code, was developed in 1964 at Dartmouth College by John Kemeny and Thomas Kurtz. Less powerful, but simpler and easier to learn than other high-level programming languages extant at the time, BASIC was initially used as a teaching tool for introducing undergraduates to the fundamentals of programming and programming languages.
Original BASIC lacks many flow control features of newer, structured programming languages and relies heavily on the use of “Go To” statements, a practice that tends to adversely impact code brevity and clarity and that has since been eschewed in more modern languages such as C++ and Java.
The Role of VBScript on the Internet and Its Relation to Other Internet Scripting Languages
For many purposes, VBScript may simply be thought of as VBA for the Web. Certainly this appears to be the primary role initially envisioned for the language by Microsoft. It allows programmers versed in Visual Basic or VBA to leverage their expertise and experience to quickly create client-side and server-side Web applications.
VBScript will run on Windows NT 4 and later, Windows 95 and later, Windows 2000, and Windows XP. However, because JavaScript had a head start as a client-side Web programming language, because native support for VBScript applications has not yet been added to the Netscape Web browser (while on the other hand, Microsoft Internet Explorer does natively support the use of JavaScript for client-side scripting), and because VBScript imposes generally fewer “sandbox” (i.e., security) restrictions than JavaScript, VBScript remains relatively less popular than JavaScript for Web client-side implementations.
How Microsoft Implements Scripting Languages
The Microsoft model of scripting distinguishes between “scripting hosts” and “scripting engines.” Scripting engines process and execute scripts fed to them by scripting hosts. Scripting hosts are applications that provide script context and environment (including a host application object model) and instantiate instances of appropriate scripting engines to execute scripts. This modular approach to scripting allows multiple applications to use the same scripting engine.
It also allows multiple scripting engines, each designed to handle a particular language of script, to support a single application. Microsoft has supplied scripting engines for JScript and VBScript as part of the Windows operating system since release of Microsoft Windows 98. Scripting engines for PerlScript, REXX, and Python are available from third parties. Microsoft also provides sufficient information about scripting interfaces to allow programmers to build their own scripting engines.
VBScript Version History
By design most VBScript upgrades have been synchronized with scripting host releases and upgrades (Microsoft, 2002b). VBScript through version 5.6, which was released in 2001. Effective with this release, version numbering for the WSH, VBScript, JScript, etc. have been made consistent. (Thus, VBScript release 5.6 coincides with WSH release 5.6.) The first three major version releases of VBScript coincided with first releases of new scripting hosts.
Last word
Version 4 was released to coincide with the release of version 6.0 of Microsoft Visual Studio, but added no notable new language features. Version 5 added several new language features and has been maintained for more than two years with minor release updates, most associated with updates in scripting hosts. With the release of Visual Basic.NET, there is no longer a clear need for a separate Visual Basic scripting language. Release 5.6 may be the last release of VBScript.
