The revolution goes by the unlikely acronym of RSS Rich Site Summary or Really Simple Syndication. RSS is a format for publishing information. It uses XML, and can be read and understood by specialised programs. It has so far become popular in the world of blogs, where many blogs have an RSS feed that is updated at the same time as the blog contents. The specialised program called as an RSS aggregator or a news reader can pick up these feeds, each of which has a unique web address. The program then splits the feed into its components and shows the most recently updated content to the end user.
RSS has been around for some time. So have the RSS aggregators. Why then has this not resulted in the PubSubWeb revolution we talk about? There have been two problems: the first, reading has meant requiring users to download a special program and install it on ones desktop, and second, RSS has been seen as a by-product of blogs, rather than vice-versa. So, what is changing?
The solution to the first problem is to use the email client itself as the news reader. Most news readers have a similar 3-pane look-and-feel; there is no need for a separate application. Email clients are ubiquitous and everyone knows how to use them. By creating an RSS aggregator which makes available the feeds as email in an IMAP account, the potential market for readers can be increased to every Internet user, rather than a small fraction which has downloaded and installed a special application. In a way, the RSS-to-IMAP service can be thought of as spam-free mail.
The solution to the second problem requires a change in outlook. The focus needs to shift from what blogs can do to what RSS can do. RSS is the harbinger of the revolution by providing a standardised way to publish and subscribe to information. What is needed is not tools to make publishing blogs easier, but publishing RSS easier. (If blogs are a by-product of the RSS publishing process, that is fine.)
There are other elements which are needed to complete the ecosystem. We need an RSS generator, which can take existing sites and create feeds for them at least till the next generation of content management tools and website publishing tools make an RSS feed (or even an XML file) as a standard, alternate representation. We need an RSS directory, to discover RSS feeds we need a Yahoo or DMOZ for RSS. We need support for authentication, so access to RSS feeds can be restricted.
We also need agents, which can be attached to RSS aggregators and wake-up to send alerts only when the specified conditions are met. This can also be thought of as a mechanism to monitor events and then report on the exceptions that happen (which are events which satisfy certain conditions).
The PubSubWeb is the next upgrade to the web as we know it today. The tools are almost there. What is needed is for service providers to aggregate these tools and integrate them in a seamless manner to build a complete information and events refinery. It will create for a richer view of the diversity that is out there in terms of content along with delivery of events and information to the people who need them most. The PubSubWeb is an idea whose time has come.
Tomorrow: Information Marketplace