InformationWeek

Rating The Push Products

The Internet may become your company's primary source of personalized news. These nine push clients have the technology to make it so.

By Jason Levitt
Issue date: April 28, 1997

You need the m ost current information, and you need it now. In the past, you might have turned to TV, radio, or newspapers, but emerging "push" technologies may make the Internet your primary news source. Push client software lets Internet and intranet users customize delivery of information directly to their desktops from a variety of sources, making it an invaluable resource for business users who rely on the latest headlines or stock prices for critical decision-making. But the promise of push technologies is far greater than mere delivery of the latest headlines. By tying together such diverse sources as live audio and video feeds, Web server content, and corporate databases, push technologies have the potential to deliver rich multimedia and software distribution both inside and outside corporate firewalls. Any of the nine push clients reviewed in this article will offer up news and information, but so will any Web browser. The added value of these push clients are personalization of information, some level of real-ti me notification of updated content, and in some cases, intranet infrastructure. The word push isn't an accurate description of how these client programs operate. Push suggests that clients are notified automatically whenever new content is available. Of the nine products reviewed, only Incisa from Wayfarer Communications in Mountain View, Calif., comes close to that model; it uses a proprietary protocol to accomplish it. The other eight products use a subscription model, where clients poll the content servers at predefined intervals to see if new content is available.

Push comes from server push, a term used to describe the streaming of updated Web-page contents from the Web server to the browser. This streaming is accomplished by keeping the connection between Web browser and server open after a Web page is downloaded. Before animated GIFs became widely implemented in Web browsers, server push was used for Web page animation by programming the Web server to continually send updated images to the browser.

The nine push clients reviewed by InformationWeek Labs this week all run unobtrusively in the background and automatically download information to your desktop while you do other tasks. Although a few of the clients can deliver software or multimedia, all are designed to deliver news and information. All are very similar from an end-user standpoint. Users can customize the interface to deliver only certain channels-a channel is a category of information offered by a content provider such as Reuters' financial news service. Incisa and PointCast from PointCast Inc. in Cupertino, Calif., are channel aggregators, which means they collect content from various sources and serve the content to the push client.

When new information is delivered, push clients notify users through E-mail, playing a sound, displaying an icon on the desktop, popping up the application, or displaying headlines on a screen saver, wallpaper, or a scrolling ticker tape.

Beyond simple graphical user interfaces, the behind-the-sce nes features are somewhat different and definitely proprietary. Some products use HTTP to download content index files; some also intercept HTTP requests between your browser and TCP/IP stack.

Push clients are only one piece of the equation. Each push client has a proprietary method for implementing content channels and usually makes a developers' kit available for that purpose. In some cases, content providers need to use special server software to offer a channel. For corporate intranets, where many desktops run push clients, some push client vendors offer a caching server that runs locally on the intranet and provides shared content feeds for all the desktops, alleviating firewall traffic.

BackWeb
BackWeb is one of two reviewed clients that can deliver multimedia content for a richer presentation of information, including animation. (Marimba Castanet from Marimba Inc. in Palo Alto, Calif., is the other.) Although BackWeb Technologies' client, server, and developers' tools offer a comple te solution for content providers and users, they do so using proprietary formats.

BackWeb's Infopak information-delivery programs, which must be downloaded every time users get new information, are typically 100 to 400 Kbytes in size, which can put a strain on disk space and network bandwidth. To lighten the load on LANs, BackWeb suggests using its "polite agent," which delivers packets only when your LAN or machine isn't busy and uses the more efficient, less demanding UDP (User Datagram Protocol) instead of HTTP to deliver content. If your firewall won't let in UDP packets, you can still use HTTP. To conserve disk space, BackWeb lets users set per-channel disk-space quotas.

BackWeb's Infopaks are essentially scripted packages of multimedia content similar in spirit to Macromedia's Shockwave program. Using BackWeb's scripting language, you can package Java applets, graphics files, audio files, and wallpapers into an Infopak. In fact, BackWeb has even created a scripting language, called BALI (Backwa rd Authoring Language Interface), that is similar to Macromedia's Lingo scripting language.

BackWeb's financial plan is to charge content providers on a per-user basis. Content providers purchase the BackWeb server and are charged a per-user fee for subscribers. That strategy is questionable, however, since content providers may ultimately have to charge users for access or get advertisers to sign on..

The BackWeb server is used both by content providers and within corporate intranets, where specialized channels can be created to deliver information companywide.

Downtown
Downtown's client GUI leaves something to be desired. Under Windows 95, it consists of a bar-similar to the Windows 95 task bar-that sits on an edge of the user's screen not used by the Windows 95 task bar. For each subscribed channel, a small, adjustable scroll bar rests on the task bar and, optionally, scrolls headlines from right to left, or just does simple animation if the channel doesn't offer headlines. But it's cumbersome to view, and if you have the animation or scrolling turned on, it's just distracting. It also has an annoying habit of moving your desktop icons when you exit.

On the plus side, InCommon LLC's product makes it easy to add your own channels, provided those channels are just Web pages.

In order to speed access to content, Downtown sets up a mini Web server on the user's hard disk and installs it automatically as the HTTP proxy server for the user's Web browser. Thus, all HTTP requests and downloads are filtered through the mini Web server before they reach the browser. Although Downtown will use the browser's existing proxy settings to get outside the corporate firewall, other browser add-ons, such as some plug-ins, may conflict with this arrangement.

Users get only a few customization choices when they subscribe to a channel, which is the only news filtering that Downtown offers.

InCommon, in San Mateo, Calif., has not made its intranet server or development tools commercially avail able, so I was not able to work with those products.

Headliner
With no shipping server nor developers' toolkit, Lanacom Inc.'s Headliner is a basic, standalone push client. But its well-engineered user interface stands out. I liked the way I could tell it to connect at any time, and its status window always showed me what was going on with my subscribed channel. The main Headliner GUI shows subscribed sites with a hierarchical view similar to Windows 95 Explorer.

Headliner is a classic push client in every respect. Subscribing to a channel downloads a content agent -a script that describes the structure and layout of the channel's Web site. Channel updates occur when Headliner polls the site at user-defined intervals. Users cannot create their own channels.

As it stands, Headliner is not an acceptable solution for corporate intranets, but it's great for standalone desktop users who just want headlines and stories. It has the added bonus of being free. Lanacom, in Toronto, will deliver its next-generation client, Headliner Professional, in May, at which point it will start charging for it.

Incisa
Incisa offers a lot of control for corporate users who want to deploy an intranet. Incisa is unique in that intra-net users stay connected to the local Incisa server. Incisa uses a proprietary protocol that runs on top of TCP/IP to maintain a stateful connection between client and server, so that Incisa can push

the latest information directly to users instead of polling sources periodically. In practice, however, polling regularly will usually deliver updated information within 15 minutes. But Incisa is worth implementing if time is critical for your company.

The Incisa server uniquely maintains a user and group database, which gives the administrator more leverage to customize user or group desktops. Administrators can create groups that receive certain content and can then add users to the group.

Incisa's GUI client delivers headlines using reusable Shockwave animatio ns combined with custom graphics and sound. By reusing the same Shockwave animations with different headlines, Incisa preserves bandwidth, since Shockwave animations don't have to be downloaded with each new headline.

I liked Incisa's administrative interface, which lets administrators create installable clients with configuration options preset and locked down to desired settings. Administration of users' desktops is easier than with push clients that users must manually configure.

Intermind
Intermind's key advantage is its use of a Netscape Navigator or Microsoft Internet Explorer as a user interface. That means any firewall supported by your browser will work with Intermind. It also means administrators don't have to support another desktop application.

Intermind maintains a database of information on a user's hard drive from which it builds HTML pages that are presented in their browser. Intermind has also come up with a straightforward way to represent channels that is similar in spirit to Microsoft's proposed Channel Definition Format. Migrating to CDF, if it becomes a standard, might be easier for Intermind than for vendors with other proprietary formats.

Intermind's channel connection files, which describe the information format and the update interval, reside on the content provider's Web server, and clients download them to subscribe to the channel. The Intermind push client wizard helps you create channels and automatically add them to Intermind's global directory of channels so that others can also subscribe to them.

Intermind does not sell a server for corporate intranets, but the Seattle company does sell a command-line developers' tool, called Dynamic Publisher, for sites that want to turn databases or other information sources into connection files. Considering that developers still have to write glue code in Common Gateway Interface or Web server APIs in order to use Dynamic Publisher, the $15,000 price seems a bit high.

Marimba Castanet
If business -critical applications written in Java were really widely used, then Marimba's Castanet suite of push products would be a hot ticket for deploying both inside and outside corporate intranets. Instead, the company's Tuner push client, Transmitter push content server, and Bongo authoring tool are more of a cutting-edge display of Java programming than anything else. This also makes Marimba unique in that it's not really designed to deliver the latest news-it's designed to deliver Java software, although Castanet can download channels that are Java applets, applications, and even HTML pages.

Once a Java application is downloaded to your desktop, it's maintained and updated via the Tuner. Bongo makes it easy for Java developers to deploy Java applications or applets via a publishing wizard.

As a Java application, the Castanet Tuner lacks some of the bells and whistles of the other clients because the Java APIs don't yet support that functionality under Windows 95. For example, there are no screen-saver, w allpaper, or ticker-tape notifications of new content. On the other hand, Java lets Marimba port its products quickly to other platforms (Bongo already runs on Solaris, Macintosh, Windows 95, and Windows NT).

Marimba has commissioned two excellent books on its tools by well-known authors: Official Guide To Castanet by Laura Lemay and Official Guide To Bongo by Danny Goodman, both published this year by Sams Publications of Indianapolis.

NetDelivery
I was frustrated with NetDelivery Corp.'s GUI, partly because of the Fort Collins, Colo., company's marketing strategy, but also because its products are not as mature as others in this review.

NetDelivery charges content providers each time news is delivered to end users. Consequently, update schedules are set by the content provider, so users can't request deliveries whenever they want. When I subscribed to new channels, it sometimes took 30 minutes before information was delivered to my desktop.

The beta of NetDelivery's development t ool shows promise. Its wizard-like interface connects providers to NetDelivery's database to register their Web sites as channels.

PointCast
The PointCast client offers rock-solid delivery of headlines and news, but its intranet I-server could use a few intranet-specific features. For example, there's no way to limit or direct content flow to groups of intranet clients. That's because the PointCast server has no knowledge of which users are connected.

Another limitation is that companies must use Microsoft's Internet Information Server to manage and serve up corporate information within the intranet. Given that the majority of Web servers run on Unix, this is a serious limitation.

PointCast is a channel aggregator-which is good because PointCast can easily offer content personalization and carefully control what's offered. But it's bad because users are limited to the 24 channels that PointCast offers.

On the desktop, PointCast offers a beautiful user interface, which includes rich graphics, text, and animations. If you don't mind the advertisements, the display is useful and enjoyable. For viewing articles, users can use the built-in browser or have all content handed off to their browser. PointCast's browser is no match for Internet Explorer or Navigator since it doesn't support Java, scripting languages, or advanced HTML. It's designed just to display basic news pages with HTML and graphics.

Transceive
I like Caravelle Inc.'s simple HTTP-based approach. The Ottawa company's Receiver, Producer, and Publisher products are on the expensive side, but they can be deployed quickly with existing Web clients and servers.

Caravelle's channels are simply Web pages, and the vendor uses HTTP to determine if a channel has been updated by checking the page's last modification date. Creating channels is trivial because a channel is just a Web page. By the same token, the Caravelle channels won't give you specific information packaged in specific headlines; you just get the targ et Web page.

Caravelle's Producer, like Incisa, lets you create customized Receivers with the options locked down, making it easy for an administrator. The Caravelle Publisher monitors files on the content provider's system for updates and then posts the modified files to your Web server so that Receiver clients can access the new information.

Push's future is the unification of corporate information, news sources, software administration, and multimedia content. For now, however, users will have to be satisfied with basic news and information, along with some bells and whistles.

See related story: " Microsoft Pushes Standards "

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