JavaScript is a scripting language designed for adding interactivity to HTML pages. The language was first implemented by Netscape Communications in Netscape Navigator 2 beta (1995). JavaScript is different from the Java language (developed at Sun Microsystems).

JavaScript programs, or scripts, are usually embedded directly in HTML files. The script executes when the user's browser opens the HTML file. (There is also server-side JavaScript, but it's beyond the scope of this FAQ collection.)

JavaScript is an interpreted language. This means that scripts execute without preliminary compilation, i.e. without conversion of the script text into a system-dependent machine code. The user's browser interprets the script, that is, analyzes and immediately executes it. JavaScript is supported by the following browsers:

• Netscape Navigator (beginning with version 2.0)
• Microsoft Internet Explorer (beginning with version 3.0)
• Any other browser/product whose vendor licensed or implemented JavaScript interpreter (for example, Opera).

JavaScript is one of the most popular tools for adding interactive features to Web pages.

JavaScript is a fairly universal extension to HTML that can enhance the user experience through event handling and client-side execution, while extending a Web developer's control over the client's browser.

• http://www.javascript.com