| The JavaScript language was developed by the Netscape
Communications Corporation and is a trademarked name.
It is a cross-platform, object-based scripting language
that was originally designed for use in Netscape Navigator.
Indeed, versions 2.0, and later, of Navigator can interpret
JavaScript statements that are embedded within HTML code.
When a request is made to see a page, the HTML code that
defines the requested page along with the embedded JavaScript
statements, are sent by the server to the client. Navigator
interprets the HTML document and executes the JavaScript
code. The resultant page is displayed for the client.
It is important to understand that this interpretation
occurs on the client-side rather than the server-side.
After the success of JavaScript in Navigator 2.0, the
Microsoft Corporation was quick to create a clone of
JavaScript, called JScript, which is a trademarked name,
that is designed to run inside the Microsoft Internet
Explorer. In truth, except for a few minor differences,
JScript is essentially a carbon copy of JavaScript.
The latest versions of JavaScript and JScript are compliant
with the European Computer Manufacturing Association's
ECMAScript Language Specification (ECMA-262 standard,
for short). Note that the name for this ECMA-262 language
is ECMAScript. However, Netscape will continue to use
the name, JavaScript and, likewise, Microsoft will continue
to use the name, JScript. It is important to understand
that the ECMA-262 standards sets minimum compatibility
requirements.
You should expect current and future versions of both
JavaScript and JScript to also contain additional proprietary
features, beyond the minimum requirements, designed
to woo the developer to favor one language over the
other. Fortunately, both Microsoft and Netscape have
promised to submit new features to ECMA for inclusion
in the evolving ECMA-262 standard. Many older browsers
are, of course, still very happily utilizing older,
non-compliant versions of these scripting languages.
JavaScript is a simple to comprehend, easy to use,
general purpose scripting language. When used in conjunction
with a Web browser's Document Object Model (DOM), it
can produce powerful dynamic HTML browser-based applications
which also can feature animation and sound.
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