JavaScript - - By Kevin Yank

Is AJAX Cross-Browser?

There is a fascinating debate going on at Dojo developer Alex Russell’s blog. Sparked over the release of ajaxWrite, an in-browser Microsoft Word look-alike, the debate calls into question just what AJAX means (if anything) for cross-browser compatibility.

Rather than using cross-browser DHTML like Writely, ajaxWrite uses Extensible User Interface Language (XUL), which means it will only work on Mozilla browsers like Firefox. Alex Russell believes that advertising such an application using the AJAX name is both misleading and harmful.

On the one hand, AJAX stands for Asynchronous JavaScript And XML. If this is taken as a complete definition of the technology, then AJAX makes no mandate as to the technology used to present an interface to the user. Though typically written using DHTML (aka DOM Scripting), user interfaces written in Mozilla’s XUL would be perfectly allowable. It is already common and accepted practice to do away with the “X” in AJAX by using lighter data transfer formats like JSON (AJAJ?).

On the other hand, the biggest benefit of most AJAX applications over alternatives like ActiveX, Flash and Java Applets is that it will work across browsers regardless of available plug-ins or proprietary technologies. To corrupt this implied benefit of AJAX by using the name to promote a product that uses browser-specific user interface technology, argues Alex Russell, is an “abomination” of “shameless marketing”.

Meanwhile, ajaxWrite developer Michael Robertson has declared that “ajaxWrite is just the beginning” — his company has pledged to launch a new application every Wednesday, reachable via It would be reasonable to expect these will all feature XUL interfaces, and names beginning with “ajax”.