Beating the Bloat

A powerful motivator of the shift to component software is the revolt that has been brewing in corporate IT departments against the expense and difficulty of maintaining modern PCs. Currently the debate rages over whether the network computer (NC) is a viable alternative. One way you might view the contest between the NC and PC camps is as two ends of a continuous spectrum of software location.

"Local storage is just a replacement for bandwidth -- it's caching," says Miko Matsumura, Java Evangelist at JavaSoft. "On a stand-alone PC (zero bandwidth) you need to store your entire universe locally, while at the oth er extreme (infinite bandwidth) you'd never store any code locally but get just what you need off the network."

Matsumura sees a third way to go: "Nobody today has unlimited bandwidth, but solutions like Marimba's Castanet allow you to mix and match the functions you want to store locally -- a 'build your own' OS."

Castanet distributes Java software using a radio metaphor, "transmitting" programs down "channels" to a "tuner" installed on your PC. Each Java program has an associated channel, and when you first subscribe to this channel the software gets downloaded to your local disk; however, the code isn't discarded as usual when you finish using it but remains on your hard disk. Whenever an update to this software is released, patches containing just the changes will be automatically downloaded and applied next time you tune to the channel. This mechanism can equally work for data updates, like changing stock prices or news items. After using Castanet for a while you'll find just the data and programs you use a lot have become stored on your local hard disk, though much more is still available on the Web at the cost of a little more download time; it's a kind of persistent caching (similar in principle to the way that America Online distributes its screen graphics). Microsoft and Netscape have made deals with the PointCast on-line news network, which offers a roughly similar kind of service, and this may figure into Microsoft's Zero Administration initiative.