1.4 JavaScript in Other Contexts

JavaScript is a general-purpose programming language; its use is not restricted to web browsers. JavaScript was designed to be embedded within, and provide scripting capabilities for, any application. From the earliest days, in fact, Netscape's web servers included a JavaScript interpreter, so that server-side scripts could be written in JavaScript. Similarly, Microsoft uses its JScript interpreter in its IIS web server and in its Windows Scripting Host product, in addition to using it in Internet Explorer.

Both Netscape and Microsoft have made their JavaScript interpreters available to companies and programmers who want to embed them in their applications. Netscape's interpreter was released as open source and is now available through the Mozilla organization (see http://www.mozilla.org/js/). Mozilla actually provides two different versions of the JavaScript 1.5 interpreter. One is written in C and is called "SpiderMonkey." The other is written in Java and, in a flattering reference to this book, is called "Rhino."

We can expect to see more and more applications that use JavaScript as an embedded scripting language.^[1] If you are writing scripts for such an application, you'll find the first half of this book, documenting the core language, to be useful. The web-browser specific chapters, however, will probably not be applicable to your scripts.

^[1] ActionScript, the scripting language available in Macromedia's Flash 5, is modeled after the ECMAScript standard, but it is not actually JavaScript.