As is the tradition when Google launches a new service, curious hackers immediately took Google Maps apart to see how the magic was done. The best early analysis came from Joel Webber, who worked out the details of image tiling, dynamic updating, and route plotting (infoworld.com/2533). Among other interesting discoveries, he found that the application uses the browsers built-in XSLT engine to transform packets of XML received from the server into search results, displayed as HTML.
This explains why Google Maps supports only Internet Explorer or Mozilla-based browsers. The others, notably Safari and Opera (Overview, Articles, Company), lack built-in XSLT processors.
Commenting on Webbers post, one reader noted that no W3C standard defines this capability. As is the related XMLHttpRequest object, which enables the browser to programmatically fetch XML from the server and parse it, the built-in XSLT processor was a Microsoft (Profile, Products, Articles) innovation that was later copied by Mozilla. Safari and Opera do support XMLHttpRequest, by the way, which is why they can run Google Suggest, the experimental version of Googles search that dynamically expands partially typed queries into lists of choices.