The Story of JavaScript

If you have a Web site that you'd like to make more interactive, you have a variety of scripting resources. For example, there's CGI, Java applets, Dynamic HTML, Perl, and VRML-all of which require a major commitment to learn. But if you're comfortable with HTML, the next logical step for increasing your Web development skills may well be JavaScript.

What is JavaScript?
JavaScript is a scripting language developed by Netscape to add interactive features to Web documents. With JavaScript you can perform calculations, check forms, write interactive games, customize graphics selections, capture events (such as mouse clicks or keystrokes), create security passwords, mouse rollovers, form validation, live clocks, and rollover effects, as well as include other special effects.

So what's the difference between Java and JavaScript? Java is a compiled programming language, similar to C or C++. It's powerful enough to write major applications such as a Web browser or small applications called "applets" that perform just a few functions and which you can insert into a Web page. Java also requires considerable effort to master.

JavaScript is based on the Java programming language, but it differs from true programming languages in several ways. First, JavaScript is much simpler than a genuine programming language, so it's relatively easy to learn. In fact, JavaScript is more on the scale of HTML than a true programming language such as Java. JavaScript requires no compiling (a process of translating computer code into an executable form). JavaScript is embedded within the HTML of a Web page and executed by the browser, so it requires no additional files (such as an applet .class file) to perform its functions.

JavaScript runs on Netscape Navigator 2.x, 3.x, and 4.x and Internet Explorer 3.x (in most cases) and Internet Explorer 4.x. Because some JavaScript functions aren't compatible with Internet Explorer it's always best to test your JavaScript functions in Both Internet Explorer and Netscape Navigator before you upload the script to the Internet. If you forgo this test, some visitors to your site may not be able to properly view your JavaScripts.

A Bit of History
JavaScript began as LiveScript, an object oriented programming language created by Netscape and Sun. The programmers who created JavaScript (nee LiveScript) wanted to create a language that would create simple scripts and embed them directly into HTML. Embedding the scripts into HTML would allow events and effects to happen on a Web page without invoking a helper program or plug-in.

Because LiveScript was created at the same time Sun was developing the language that eventually became Java, the red-hot, platform-neutral programming language, there are some internal similarities between the two languages. Although it was released before Java, LiveScript was renamed JavaScript to capitalize on Java's name-recognition.