IDEA No 74
AJAX
Short for ‘asynchronous JavaScript and XML’, AJAX is a group of interrelated web-programming technologies that can send and retrieve data in the background, without having to reload the page.
In the early years of the Web, pages were built entirely in HTML. On each click, a new page was loaded. Even a small change to the page meant the entire page had to be refreshed. On the plus side, it was easy to create webpages; on the down side, it led to a stop-start user experience.
In 1999, Internet Explorer 5 introduced the XMLHttpRequest, using it to dynamically update the news stories on the MSN homepage. This functionality was soon adopted by all major browsers, and the Web made a gradual transition from static to dynamic pages. The roots of AJAX had been established.
Then, in 2004, John Battelle and Tim O’Reilly held the first Web 2.0 Conference. Their opening remarks, described the future of the Web as a platform. Whereas Web 1.0 companies, such as Netscape, created software for the Web, Web 2.0 companies, like Google, created software on the Web.
Over the next couple of years Google confirmed Battelle and O’Reilly’s prediction. Services such as Gmail, Google Maps and Google Calendar were more like software than webpages. In February 2005, Jesse James Garrett assessed the technologies these services were built on and described them collectively as AJAX. The term stuck.
Web 2.0 companies that base their services on AJAX share few of the characteristics of a traditional software company. Their software does not come in a box. There is no licence and no scheduled releases, just ongoing improvement.
AJAX represents a fundamental shift in what is possible on the Web. Not only does it eliminate the stop-start nature of websites, but it also reduces the amount of data transferred between the server and the browser, and so speeds up response times. Websites become a seamless combination of software and data. In fact, the data is central to Web 2.0 companies: Google has an index of links, Google Maps has geographical data, Amazon a catalogue of products, Flickr an image collection, Facebook a dossier of our lives.
AJAX technologies allow web applications to access these databases in a fluid and meaningful way. They move websites beyond pages to dynamic environments that are a joy to explore. Web 2.0 is not hyperbole, it’s a useful description of a Web that works.■
‘A seamless combination of software and data.’
WasteLandscape, by Elise Morin, is a 500m2 (5,382ft2) artificial undulating landscape of 65,000 unsold CDs.