A Little History Lesson

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Years ago, the programmers at Netscape Communications Corporation recognized that HTML alone was not robust enough to support interactive Web programming. In 1995 they developed a scripting language called LiveScript, which gave Web page developers greater control over the browser.

Later, Sun Microsystems came along and developed a new programming language named Java. Java quickly became a hot item and received an enormous amount of media and industry attention. Netscape added support for Java in Netscape Navigator 2. At the same time, Netscape decided to change the name of LiveScript to JavaScript, which earned the scripting language a little more attention thanks to its name . That's about all the two languages have in common. Neither is related to the other, although both are supported by modern Internet browsers as a way of delivering interactive Web content.

Netscape has continued to enhance and improve JavaScript over the years and has released a number of new versions of Netscape Navigator along the way, as shown in Table 1.1.

Table 1.1. HISTORICAL VIEW OF INTERNET BROWSER SUPPORT FOR JAVASCRIPT

JavaScript	Netscape Version	Internet Explorer Version
1.0	Navigator 2	Internet Explorer 3
1.1	Navigator 3	Internet Explorer 4
1.2	Navigator 4	Internet Explorer 4
1.3	Navigator 4.5	Internet Explorer 5
1.5	Navigator 6 and 7	Internet Explorer 5.5 and 6

One problem that has plagued Internet development over the years is a lack of standardization. The European Computer Manufacturing Association (ECMA) has taken a lead role in working toward standardizing JavaScript, which it refers to as ECMAScript. The ECMA-262 specification outlines standards with which JavaScript 1.3 is compliant. JavaScript 1.5 is compliant with ECMA-262 revision 3.

Like the JavaScript 1.5, JScript 5.6 is a based on ECMA-262 revision 3.

NOTE

Netscape is now working on JavaScript 2.0, which it promises will be compatible with the fourth revision of ECMAScript. At the same time, JScript .NET, Microsoft's next version of JScript, is also being developed based on ECMAScript revision 4.

Microsoft first released JScript in 1996 as a scripting language for Internet Explorer 3.0, which was basically just Microsoft's own implementation of JavaScript 1.0. Later, JScript 2 was released as a component of IIS 3.0, turning JScript into a server-side scripting language that, when embedded inside ASP pages, could access server-side databases and create HTML pages with dynamic content.

NOTE

Internet Information Server (IIS) is a Microsoft Web server application that supports the creation of Web sites and is used by companies all over the world to host their Web sites. Active Server Pages (ASPs) are executable files that run on IIS and deliver dynamic HTML content.

JScript 3 was released in a number of different environments, which include the following:

Internet Explorer 4
IIS 4
Windows Scripting Host

As one of the two default scripting languages provided as part of Microsoft's new Windows Scripting Host, JScript 3 became a desktop scripting language capable of interacting directly with computer resources. Next, JScript 4 was delivered as part of Microsoft's Visual Studio development suite. The major feature added to this version of JScript was the capability to interact directly with the Windows file system.

NOTE

Microsoft's Visual Studio development suite is a collection of different software languages and software development tools that assist software developers in creating robust professional applications.

JScript version 5 was released along with the joint introduction of Internet Explorer 5 and Windows 2000. The current version of JScript, version 5.6, was introduced in 2001 along with Windows XP and Internet Explorer 6.

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