On Tuesday, Microsoft announced the first open-standard format for delivering push content on the Web.
The Channel Definition Format (CDF) announcement was made prior to the opening of Internet World Expo in Los Angeles, and was followed by a clamor of supporting statements by many of the Internet's largest content providers and server developers, including America Online, AirMedia, BackWeb, PointCast, and Wired Ventures, Inc., publisher of Wired News.
CDF is actually a standard way to describe a Web site, said Yusuf Mehdi, group manager of Microsoft's Internet Division. "CDF is like a map for a Web site: Here's the information that I have stored on my Web site; here's how often I update it; here are the different categories. It maps all this information out into a little file. Then the browser reads that file and knows what information to get and when to get it."
The alternative, built into Internet Explorer 4.0, Mehdi said, is for a Web crawler to search for all of the relevant information on the server then report back to the client, which can then receive information pushed from the server. The problem is that the search takes time and server resources.
The CDF format spares the server this drain by explicitly telling the browser what information is available. By combining the CDF file with a small application cookie, users can get customized information from a server, Mehdi said. The system offers low overhead to publishers, since the CDF file can be written in an application that supports HTML, and the Web site itself needs no modification.
IE 4.0 will support CDF, meaning users will be able to view pushed CDF content in the browser. CDF is the first open standard for push technology, but other formats, such as Netscape's Constellation, are in the works. However, there is nothing to stop Netscape from implementing CDF, which hit the ground running with impressive momentum.
"Netscape can use the standard, and we hope they get behind it like the rest of the industry and support CDF in their browser," Mehdi said. Microsoft has submitted the format to the World Wide Web Consortium for consideration as an Internet standard.
PointCast followed up Microsoft's news with its own announcement Wednesday of the PointCast Connections service. The company said the new service will let any publisher push content, for free, through its PointCast Network browser.
PointCast co-developed CDF with Microsoft to make PointCast Connections feasible. The company hopes the new model will bring more viewers, and ultimately, more advertising, to the PointCast Network.
