Publish-Subscribe: Various information sources can publish their RSS feeds, but how do we find out about them and get to the events that are of interest to us? This is where the notion of publish-subscribe comes in. Think of the analogy from Instant Messaging. When we go online, our friends instantly know we are online because they have subscribed to our presence information. Similarly, we should be able to set up subscription interests for RSS feeds and events, and have them delivered to our personal RSS Aggregator on the desktop. Together with blogs and RSS feeds, publish-subscribe enables information to be narrowcasted within the enterprise and on the Internet.
Outlines: Most of us think top-down, in outline format. It is a surprise then that outlines have not really taken off in as a publishing format. One could think of presentations as outlines, but thats only a small subset of how outlines could be used. Outlines can be used in two-ways: through a collapse-expand interface, they can be used to show a lot more information on the desktop giving the user control on what is to be seen, and by enabling users to collect their ideas on specific topics and make directories with links to their own postings or transcluded links to other directories. [Transclusion means including in-place, much like images are shown in-place on a web page even though they may be coming from different locations.]
Open Source: Because Microsoft tightly controls the Windows APIs, it may not be easy to implement the new desktop ideas on the Windows platform. However, think of Linux and the situation is different, because the source code is open and free. Four applications have the potential to become platforms: Mozilla, Evolution, OpenOffice and GAIM. Already, GAIM has become a unified instant messaging application, connecting to any of the other proprietary IM universes. OpenOffice uses XML as its data storage format. Evolution (which has email, calendar, contacts and to-do lists) can be extended to do the same. Mozilla is much more than a web browser, given the development activity brewing around it.
XML and Web Services: They key is to separate the open source applications into three components: the display, the processing logic and the storage. This way, the logic can be taken inside out and exposed as a web service.Storage can be in XML thus allowing for exchange with other applications. The display can be a customized, two-way enabled web browser (with a micro web server in-built to facilitate real-time updates).
IM/SMS: Instant Messaging and Short Messaging Service bridge the distance to the user. IM can provide updates through the presence and publish-subscribe hooks when something changes, while SMS can be used to send alerts on a cellphone when a user is offline. Together, they ensure that, in this era of near-ubiquitous connectivity, we are never too far away from the information that we need.
So, the next question is: how do we take all these components and build the Digital Dashboard as the next-generation desktop?
Next Week: The Digital Dashboard