by David Strom
(ran in Network Computing 2/15/97)
Delivering customized content using standard tools such as web servers and browsers is now possible, and there are many products to choose from.
One of the best demonstrations of Intranet applications is the ability to target particular desktops within your corporation for specific announcements or content. Does your Human Resources department want to tell just department management about the effect of new work rules? Or will everyone in Manufacturing need to know about a new price increase in a critical part?
There are various terms to describe this, depending on which media you use for your analogies. The print trade calls this push-publishing, while the TV and radio broadcast industries call this narrow-casting. Whatever you call it, this has become a widely popular product category in the past year. Just take a look at for our list of push technologies.
Push-publishing makes a great deal of sense for your Intranet. You can target specific users with specific content, as well as notify them of changes to existing content and draw attention to particular trends or reports. You can use these technologies to distribute software upgrades, or at least notify users when new versions become available. And when push-publishing is combined with existing technologies such as web and email, you have a very powerful electronic publishing platform that can become a solid core for building other Intranet applications.
Intranet-based push-publishing as a category has seen a great of deal of change over the past year. Indeed, twelve months ago none of the products from companies such as Intermind, BackWeb, Broadvision, or Caravelle even existed! And naturally, NT has been at the center of many vendors' strategies. Most of the products covered here have NT versions for clients, servers, or both.
So how to pick? Let's start out by reviewing what kinds of publishing requirements you might have.
First off, do you want to become your own content publisher, or are you interested in subscribing to existing content that is prepared by others? Products from Intermind and BackWeb are better if you are going to do the former and direct your users to your own content; while products from Lanacom and PointCast are better for directing users to others' content.
If you have a broad mix of browsers and operating system versions you'll find that most of these products are going to be a difficult sell: the push-publishing products work in conjunction with a web browser for the most part. That means that you need to ensure that you have the most up-to-date versions of browsers throughout your enterprise and that the vendor supports the mix of versions of particular desktop operating systems present in your corporation. Most of the vendors are just now getting around to adding Macintosh client support for their products, and some such as NetDelivery and DataChannel don't plan on supporting Unix or OS/2 any time soon.
Next, you want to consider how you want to notify your users of new content. There are several mechanisms in use that vary in how intrusive they are to your users' computing regimen. Perhaps the most or least popular, depending on whom you ask, is the screen saver. PointCast pioneered this method over a year ago for delivering news flashes, stock quotes, and other information, and while effective it does have some disadvantages: first off, if your users aren't at their desks or actively using their computers, they won't see the screen saver. Second, it can be distracting. And it can hog network bandwidth.
An alternative to using the screen saver is to deliver a fax, an email message or a message to a pager. This works well for shorter messages, but obviously won't work if you want to deliver audio or video clips that require some solid network bandwidth. Netscape's Constellation, along with Diffusion and Cognisoft's products, are the ones to look at here. These methods can also be used to include users that are outside your own corporation, in cases where the Intranet has grown to become an "Extranet" that touches your customers and development partners.
A less intrusive method is used by Lanacom to deliver headlines inside the title bar of an application, limiting the desktop real estate that is used for scrolling messages. This is somewhat less distracting but can be disconcerting for some users. An alternative is used by Intermind, which pops up a dialog box asking if you want to receive new content? If not, you are a mouse click away from getting back to your work.
And even less distracting is the method used by BackWeb, which calls its software the "polite agent" since it doesn't interrupt what you are doing at the keyboard. Instead, it does its dirty work in the background, or when your computer isn't active doing other tasks.
Finally, you'll want to look at what server hardware and software is required and how this fits in with your existing Intranet development plans. Some of the products that work with external content, such as Lanacom's Headliner, don't currently have server components -- you can only subscribe to those channels that the folks at Lanacom have programmed into their system.
Intermind has the simplest setup: it works with most any web server, and all that is required is for the publisher to copy a special control file to the server that tells users what new content is available. This single control file, called a hyperconnector, is produced by the Intermind publishing application itself, and signals each Intermind-enabled browser when these browsers are active on the network.
More complex is BackWeb, which requires both a Unix and a Windows NT server on the network to deliver its "InfoPaks" or subscription channels to each user. The NT server manages the content on the Unix server.
And even more complex are those products such as Marmiba and Broadvision that offer complete development environments for delivering customized information. For example, Marimba has a whole series of products that allow for custom Java program delivery and content manipulation, going beyond just publishing specific content.
What will they products cost? Many of them offer their clients at no charge, but these can quickly become very pricey. A several hundred-seat BackWeb application can cost upwards of $50,000, and others are equally expensive as you add channels or seats. Given the costs, probably your best strategy is to visit a vendor's web site and download the sample client first.