想要一个WEB的革命

You Say You Want a Web Revolution 

The Netscape threat that led Microsoft to wage the browser war and cross swords with antitrust regulators around the world is -- at long last -- poised to become reality.

Software experts say recent innovations in web design are ushering in a new era for internet-based software applications, some of the best of which already rival desktop applications in power and efficiency. That’s giving software developers a wide open platform for creating new programs that have no relation to the underlying operating system that runs a PC.

Evidence of this evolution has been popping up everywhere in recent months, with examples that include Google's online map rendering software and its Gmail service, Amazon's A9 search engine and NetFlix's DVD rental platform. All highlight a dramatic rethinking of web applications, using a programming technique dubbed AJAX (for asynchronous JavaScript and XML) that significantly improves how web pages interact with data, for the first time rivaling programs that run natively on the desktop.

"For a user it is fundamentally different -- it feels like a real application," said Rael Dornfest, chief technology officer for O'Reilly Media.

AJAX overcomes a severe limitation in traditional web interfaces, which must reload anytime they try to call up new data. By contrast, AJAX lets users manipulate data without clicking through to a new page, Dornfest said. That's putting an end to page refreshes and other interruptions that have handicapped wweb-based applications until now.

Web developers are creating AJAX code libraries and conventions to ease the burden of making applications that speak several computer languages. Even Microsoft is getting into the game, albeit with hooks that aim to keep it tethered to its Windows OS. The company recently announced it is developing its own AJAX toolbox, called Atlas, for web developers who use Microsoft's ASP.NET technologies to build websites.

Perhaps the best known example of AJAX is Google Maps, whose improbable drop shadows and absurdly movable maps spread shock and awe among web developers in February.

Jesse James Garrett, a co-founder of the Adaptive Path consulting firm gave AJAX its name in an influential essay.

"The deep trend here is that we are really starting to figure out what the web is good for," he explained in an interview with Wired News. "This is the web coming into its own as a medium for software applications."

According to Garrett, designers of the first generation of web applications relied on the model of desktop software, and then dumbed them down to fit in a browser. Gmail, the Google webmail service released last year, awakened Garrett and many others to the possibility of a new style of web applications.

"Everyone thought the story of web user interface for e-mail ended in 1999," Garrett said. "Then Google comes along five years later and says 'There is more we can do here,' and demonstrated it in an uncompromising way -- not relying on Flash but simply using browser-native technologies and pushing them as far as they can go."

While Microsoft wants to be part of the AJAX revolution, its major focus for developers is on helping them build lively, multimedia Windows desktop applications for its next operating systems.

To that end, Microsoft included a user interface development tool called Windows Presentation Foundation (formerly codenamed Avalon) in last week's release of a small batch of test versions of Vista, its long-delayed successor to Windows XP.

Atlas, Microsoft's AJAX equivalent, won't likely be shown to web developers before the company's developer conference in September.

Though Microsoft may have created the foundations of AJAX in the late 1990s when it introduced the XMLHttpRequest API in Internet Explorer, and created the first AJAX application (an e-mail client for business customers on the go), the future of applications is on the desktop, according to Forest Key, a Microsoft group product manager.

"While AJAX is clearly improvement over less rich HTML stuff, it is really just a step in direction, in terms, in what users want to experience," Key said. "AJAX is nothing compared to what is coming."

"We recognize the need in certain scenarios for browser-based, standards-based stuff and that’s where we have ATLAS technology, which is going to simplify the development of AJAX content," Key said, "But when you are talking about richness and fullness and really doing amazing things that approach cinematic user interfaces, you are going to need a richer technology, and that’s what Windows Presentation Foundation is all about."

Key thinks that Vista's capabilities, combined with powerful and intuitive development tools for both the desktop and the web, are going to lead to the death of unproductive, non-intuitive computer interfaces.

"If you fast forward five years, you are going to see a huge shift in that consumers and business users will expect and demand richness and fullness in all applications," Key said.

Experts say they don't expect AJAX will make desktop applications obsolete. But it has already affirmed the viability of the web as a standalone software development platform.

"This is going to go a long way towards eliminating the user interface insults and injuries we have suffered since we moved to the web," O'Reilly’s Dornfest said. "Now people these days expect it to be flat so they might be a little surprised (by AJAX applications). But the rest of us see AJAX and say 'Ahh, this is what it is supposed to be like.'"