HTML was invented in 1990 by Tim Berners-Lee, a scientist at the European Particle Physics Laboratory (CERN). Berners-Lee was seeking to develop a means by which CERN's visiting scientists could more easily and effectively exchange information, even across otherwise-incompatible computer systems. The fruits of his labor, first used by Berners-Lee and a colleague on Christmas Day of that year, was Hypertext Transfer Protocol (HTTP), HTML, and the first browser/editor, which he dubbed WorldWideWeb.

Over the next several years, these three inventions were expanded upon by many other Web pioneers. However, the technologies would not see widespread use until 1994, the year the Netscape Corporation released its Web browser, Navigator. Navigator was the first Web browser widely available to the public. That year and the following saw the founding of such companies as Yahoo! and Amazon and also the first hints of what the Web might become.

Unfortunately, those early days also saw the first hints of what in many ways remains the biggest challenge facing Web developers around the world: browser incompatibility.

After Netscape rejected its licensing offers, Microsoft developed its own browser, Internet Explorer (IE). Microsoft placed IE on the desktop of its soon-to-be ubiquitous Windows 9x operating system. Microsoft and Netscape would battle for the next few years for market dominance in what has become known as the "Browser Wars".

This period marked a low point for Web developers, as both companies released version after version of their browsers. With each new release there were features not supported by the other company's browser. An early effort at providing basic animation on Web pages led Netscape to introduce the ill-fated blink tag. Microsoft responded with the equally ill-conceived marquee tag. As neither browser supported the other's innovation, neither tag took hold.

For some time during this period, Web design books and tutorials went so far as to advocate that developers create two separate sites; one that would display correctly in Navigator, the other in IE. Others focused on the non-too-reliable JavaScript solution of browser sniffing — using JavaScript to attempt to determine the user's browser and display browser-specific code.

All of the early versions of HTML shared one thing in common: a complete lack of capability to provide any interactivity for the users. As the Web grew in popularity and profitability, companies began demanding interactivity. This would include animation, games and ads or other areas of pages that could meaningfully respond to users. All of those capabilities existed for the development of desktop applications; why then, clients would ask, were they lacking on the Web?

An early and for a time popular solution to this lack of interactivity was Dynamic HTML (DHTML). DHTML pages contain basic HTML markup, which can then be manipulated at runtime with JavaScript. DHTML offered designers a lot of freedom to create the kinds of interactivity their clients and bosses were demanding. For the first time, Web photo galleries could be created that allowed users to simply move a mouse over a thumbnail of an image and have a larger version of that image appear automatically.

Unfortunately, DHTML suffered from the beginning from the very problem facing everyone who tried to develop Web pages: varying browser support. If Netscape and Microsoft were at odds with their support for various HTML tags, it was nothing compared to the way they handled JavaScript.

In fact, JavaScript had been developed by Netscape, and for a time was not supported at all in Internet Explorer. Microsoft had developed a competing language known not-that-creatively as Jscript, which of course was not, in turn, supported by Netscape. Even after Microsoft tacitly acknowledged that JavaScript would win that battle and introduced support for it in its browser (it would eventually abandon Jscript), it continued to support JavaScript in a slightly different form than what was used by Netscape. As a result DHTML added lots of impressive features into pages, but development of it became a nightmare. At times, a developer had to write two complete scripts, one for Navigator, the other for IE, then use complicated browser-sniffing to determine which script should be run. These issues would ultimately doom DHTML.

By the early part of this century, Netscape could no longer hold its position against Microsoft's market dominance with IE. DHTML eventually gave way to easier, more stable solutions. In large part, this was due to the end of the Browser Wars. In the late 1990s, Netscape was bought out by one-time Internet giant AOL. By the middle of the first decade of the 21st century, AOL would officially dissolve Netscape as a separate corporate entity. Navigator survives, but as little more than the official AOL browser; few if any users who are not AOL customers use Navigator.

The second factor that brought about the end of the Browser Wars was the establishment of Web standards.

Driven by a grass-roots effort of Web designers who were tired of having to deal with browser incompatibilities and having to develop and maintain separate versions of their pages, the Web standards movement advocated for a code once theory. HTML designers agreed that if one was willing to ignore browser-specific variations, it was possible to develop a page that would display near-perfectly across all browsers.

The advent of Cascading Style Sheets (CSS) provided a more powerful formatting platform for Web pages than had previously existed in HTML. JavaScript was also accepted as an open standard. These two progressions meant that it was at long last possible to develop pages guaranteed to display the same in the growing market of standards-based browsers: Minor fixes were still at times required for proper display in IE, but they were just that — minor — and more recent releases of IE promised ever-growing standards support.

At about the same time, developers noticed a little-used JavaScript method, HTTPRequest. They discovered that HTTPRequest could use JavaScript to make requests to Web servers. This enabled a designer to create pages that could, dynamically at runtime, retrieve data to update a small portion of a page. Prior to this, pages had to be completely refreshed every time they needed new data, a slow and inefficient process. As the data being retrieved with JavaScript was most often formatted using Extensible Markup Language(XML), this new method of feeding data into pages was termed AJAX, or Asynchronous JavaScript and XML.

In order to simplify the development of pages, advanced developers created Ajax libraries: code bases that enabled designers without a deep understanding of JavaScript to develop pages that used the technology. In time, libraries began to develop that had nothing to do with XML or even with retrieving data from the server, but instead merely relied on JavaScript, standards-based HTML, and CSS to dynamically redraw pages. Thus Ajax became the logical (and much more successful) successor to DHTML. Eventually, its name would be changed to reflect this reality.

Today the term Ajax is not an acronym for anything. Instead it is simply the name for this idea of using XHTML, CSS, JavaScript and XML to create interactive Web pages and for creating Rich Internet Applications.

What began as a simple animation tool has now grown into a complete platform of tools for creating animation, embedding video, and developing complete Rich Internet Applications for the browser and the desktop alike.