On April 15th, Netscape announced Netcaster (formerly code-named Constellation), their Internet push component, which is to be included in the next release of Communicator. After examining the announcement, itÆs clear that Netscape is late to the push market, and that their solution isnÆt based on industry standards. Over 30 leading content providers, including America Online, CompuServe, Starwave and Ziff Davis support MicrosoftÆs open approach to webcasting, which includes the Channel Definition Format, announced on March 12, 1997. These and many other vendors are joining with Microsoft to make webcasting a richer, standards-based communications medium.

MicrosoftÆs solution to pushing content includes open choice of content, optimized delivery, and an open transport architecture, and differs from NetscapeÆs in four key areas:

1. Webcasting of any Web site. Any existing Web content or site can be broadcast to Internet Explorer 4.0 users without any modification to the Web site or changes to the Web content.
2. Optimization of Push Content. The proposed Channel Definition Format (CDF) standard allows content providers and customers to optimize the delivery of channel information. CDF provides a description of whatÆs on the site, plus it provides mechanisms for grouping information logically, scheduling how often the content updates, and determining how to best deliver content to the user. Netscape offers no such capabilities.
3. Standards-based approach. CDF has been proposed to the World Wide Web Consortium (W3C) and is supported by almost 40 of the industryÆs leading content providers, Web and JavaÖ authoring tools vendors, and push developers. Netscape will require configuration files, and force Web developers to either use JavaScript to add channel buttons, or use the proprietary Marimba client.
4. Open Architecture. Microsoft has opened up the webcasting architecture to enable any backend push technology vendor, such as PointCast, BackWeb, Marimba, etc., to deliver their push content into a standard client, Internet Explorer 4.0, using standard protocols.

• Roaming user support
• Replication of application files
• File management functions
• User configuration of the desktop

Fact: NetcasterÆs webtop is a weak implementation of Internet ExplorerÆs Active Desktop.
Webtop adds another layer to the operating system, and is not truly integrated, as is Internet ExplorerÆs Active Desktop. It also appears that the webtop will be just a single channel that's displayed on the desktop. Active Desktop, on the other hand, allows any pages, channels, or combinations thereof to live on the desktop and be updated based on user preferences. Plus, the Active Desktop, as part of Internet Explorer 4.0, can be easily managed and configured by users, corporations, OEMs, ISPs, etc.

Fact: Netscape has taken a proprietary, limited approach to pushing content.
According to Netscape, Netcaster will require a configuration file for sites to become channels. This config file will be proprietary to Netcaster and wonÆt provide "meta" information (such as subject descriptors, keywords, identification of which parts of a site should be downloaded, etc.), as opposed to CDF, which is an open proposal to the W3C that is based on XML. And for a wider range of content delivery and application management features, Netcaster will include Marimba's Castanet client, which requires a Castanet server to push content. Contrast this with Microsoft Internet Explorer 4.0: it not only allows any Web content to be delivered, but also includes an open architecture that allows any push client or protocol to be "plugged in," giving users a consistent interface and way to access content. With Internet Explorer 4.0, content providers can webcast any Web site today without any modifications to their servers or their content.

Fact: NetscapeÆs refusal to support the open CDF standard hurts users and content providers.
Netscape has no way to provide their customers the benefits CDF offers, such as push optimization. By including a proprietary, limited approach to push content in Communicator, Netscape is ignoring the unmatched industry support for CDF, which has been endorsed by 13 push vendors, authoring tools vendors, solution providers, and over 22 content providers. Unfortunately, the people who will be hurt most by NetscapeÆs decision are Web site content developers and NetscapeÆs own customers. The emerging CDF standard offers great flexibility, allowing Web sites to choose the types of information they want to broadcast, and users to choose not only what they want to receive, but also how often and when they receive it.

Fact: Netscape is offering a more limited set of content partnerships.
Only a handful of partners have committed to NetscapeÆs Netcaster launch, most of whom are already Inbox Direct partners. Contrast this with the more than 20 content providers that have announced support for CDF, and the fact that any site on the Net today is a content provider for Internet Explorer 4.0. In addition, Internet Explorer will offer PointCast, which already brings together more content providers than the entire list Netscape has signed up. These include CNN, the Wall Street Journal, Ziff Davis, the New York Times, the LA Times, the Chicago Tribune, and more than 30 other major media companies. Plus, PointCast already has more than a million active viewers, giving it a rate base comparable to the New York Times and Business Week.

Comparative Overview of MicrosoftÆs and NetscapeÆs Webcasting Capabilities

Webcasting Features	Internet Explorer 4.0	Netscape Netcaster
Channels	Yes	Yes
Webcast any site	Yes	No
Server-side changes required	No	Yes
Channel Definition Format Standard Support	Yes	No (proprietary solution)
Optimized Delivery Options	Yes (CDF)	No
HTML-based Desktop	Yes (native)	Yes (add-on layer)
Channel Guide/Finder	Yes	Yes
Offline Features	Yes	Yes
User Configurable Desktop	Yes	No
View & Run Applications within Desktop frame	Yes	No
Single window for navigating local and Web content (Browser enabled everywhere)	Yes	No
Screen Saver for Push content	Yes	No
Easily add data from Web sites via button-click or drag/drop	Yes	No
Rearrange/resize desktop components to any position via drag/drop	Yes	No