Section 26.1. A Little Background

26.1. A Little Background

JavaScript is an object- and prototype-based programming language that got its start in 1995 as the creation of Brendan Eich at Netscape. It was originally named "Mocha" and then "LiveScript" before being confusingly re-christened JavaScript in conjunction with its release in Netscape Navigator 2.0 Beta 3 in December of 1995.

It is important to note that JavaScript is not Java. Both are similar to the C programming language and share a similar syntax, but that is pretty much where their similarity ends. The Java programming language was creating quite a stir in the computer world when Netscape was readying LiveScript for release, and, somehow, the decision was made to rename the language JavaScript to cash in on some of the buzz. Unfortunately, it did more to confuse the programming world than it did to improve the popularity of JavaScript.

JavaScript was standardized in 1996 when it was turned over to the European Computer Manufacturer's Association (ECMA) for maintenance and further development. The latest version, JavaScript 1.5, arrived in 1999 and corresponds to ECMA-262 Edition 3. Consequently, JavaScript is sometimes referred to as ECMAScript.

Microsoft offers a competing language, VBScript , based on Visual Basic, but as it is only supported in Internet Explorer, it is a poor choice for the Web. It should also be noted that Microsoft offered its own port of JavaScript, JScript, which supports most of the standard JavaScript functions (albeit in sometimes peculiar ways) and extends some functionality, but, again, only for Internet Explorer.

JavaScript does have uses beyond the browser as well. It is available in PDF documents, is a primary driver in the Mozilla platform, and even powers the Dashboard Widgets in Apple's Mac OS X 10.4 (Tiger). Using JavaScript outside of a web context is beyond the scope of this chapter, but there are many resources online if you are interested in exploring.

One thing to keep in mind about JavaScript is that it is a client-side scripting language, which means it runs on the client's machine and not on the server. This is an important distinction as it means its implementation depends on the capabilities and settings of the browser viewing the page. That is why, before we get into the nuts and bolts of writing JavaScript, we should talk about the best ways to use JavaScript.