When Virtuoso first unleashed support for XML (in-built XSL, Native XML Storage, Validating XML Parser, XPath, and XQuery) the core message was the delivery of a single server solution that would address the challenges of creating XML data.

In the year 2000 the question of the shape and form of XML data was unclear to many, and reading the article below basically took me back in time to when we released Virtuoso 2.0 (we are now at release 3.0 commercially with a 3.2 beta dropping any minute).

RSS is a great XML application, and it does a great job of demonstrating how XML --the new data access foundation layer-- will galvanize the next generation Web (I refer to this as Web 2.0.).

RSS: INJAN (It's not just about news)

RSS is not just about news, according to Ian Davis on rss-dev.
He presents a nice list of alternatives, which I reproduce here (and to which I�d add, of course, bibliography management)

  • Sitemaps: one of the S�s in RSS stands for summary. A sitemap is a summary of the content on a site, the items are pages or content areas. This is clearly a non-chronological ordering of items. Is a hierarchy of RSS sitemaps implied here � how would the linking between them work? How hard would it be to hack a web browser to pick up the RSS sitemap and display it in a sidebar when you visit the site?
  • Small ads: also known as classifieds. These expire so there�s some kind of dynamic going on here but the ordering of items isn�t necessarily chronological. How to describe the location of the seller, or the condition of the item or even the price. Not every ad is selling something � perhaps it�s to rent out a room.
  • Personals: similar model to the small ads. No prices though (I hope). Comes with a ready made vocabulary of terms that could be converted to an RDF schema. Probably should do that just for the hell of it anyway � gsoh
  • Weather reports: how about a week�s worth of weather in an RSS channel. If an item is dated in the future, should an aggregator display it before time? Alternate representations include maps of temperature and pressure etc.
  • Auctions: again, related to small ads, but these are much more time limited since there is a hard cutoff after which the auction is closed. The sequence of bids could be interesting � would it make sense to thread them like a discussion so you can see the tactics?
  • TV listings: this is definitely chronological but with a twist � the items have durations. They also have other metadata such as cast lists, classification ratings, widescreen, stereo, program type. Some types have additional information such as director and production year.
  • Top ten listings: top ten singles, books, dvds, richest people, ugliest, rear of the year etc. Not chronological, but has definate order. May update from day to day or even more often.
  • Sales reporting: imagine if every department of a company reported their sales figures via RSS. Then the divisions aggregate the departmental figures and republish to the regional offices, who aggregate and add value up the chain. The chairman of the company subscribes to one super-aggregate feed.
  • Membership lists / buddy lists: could I publish my buddy list from Jabber or other instant messengers? Maybe as an interchange format or perhaps could be used to look for shared contacts. Lots of potential overlap with FOAF here.
  • Mailing lists: or in fact any messaging system such as usenet. There are some efforts at doing this already (e.g. yahoogroups) but we need more information � threads; references; headers; links into archives.
  • Price lists / inventory: the items here are products or services. No particular ordering but it�d be nice to be able to subscribe to a catalog of products and prices from a company. The aggregator should be able to pick out price rises or bargains given enough history.

Thus, if we can comprehend RSS (the blog article below does a great job) we should be able to see the fundamental challenges that are before any organization seeking to exploit the potential of the imminent Web 2.0 inflection; how will you cost-effectively create XML data from existing data sources? Without upgrading or switching database engines, operating systems, programming languages? Put differently how can you exploit this phenomenon without losing your ever dwindling technology choices (believe me choices are dwindling fast but most are oblivious to this fact).