RSS: The Web Service We Already Have.

by Timothy Appnel

DJ Adams writes:

It seems that beyond carrying syndication information, RSS is a very useful and flexible way to get all sorts of application data pushed to a user over time. In the same way that a web browser is a universal canvas upon which limitless services and information can be painted, so (in an albeit much smaller way) an RSS reader/aggregator might also find its place as an inbox for time-related delivery of all sorts of information.

Amen DJ! As I asserted in a previous weblog post, Web Services We'd Like To See, I wrote Whether it is just assumed or simply overlooked, RSS is the most widely deployed Web service across the Internet. Granted, most RSS feeds have very simple interfaces with almost as simple backends that are unlike the Web services that usually come to mind. (Who says Web services need to be complex or sophisticated anyhow?) Under the principles of the REST architectural style that the Web was built on, RSS feeds do qualify. Consider that any site search engine becomes a Web service if it could emit results in RSS and the format's potential in the realm of Web services becomes more apparent. It is this perceived potential that I've been an advocate of getting the RSS format's house in order.

Numerous instances of the format's value in service delivery are popping up in experiments around the network. Sam Ruby's experiments with automatic linkbacks. Joe Gregorio's RESTful interface for publishing to weblogs. (On an aside, Joe and I are co-conspiracers in starting a mailing list to discuss these very notions. Come one, come all.) DJ integrates SOAP and RSS web services in his experimental booktalk application script. Matthew Langham posted here about the use of RSS in deliverying business data. There is also the on-going discussion of remote commenting and tracking using RSS.

I'm happy to see the message spreading. Today Jeremy Allaire writes in An Explosion of Web Services?:

As I've been reading and writing today I've come to a somewhat obvious conclusion: there's been an explosion of 'web services' in the past year, and it has nothing to do with SOAP, WSDL and such standards as described in the industry but with the ascending role of RSS and RDF as XML data and syndication formats.

Lots of industry analysts have commented that 'public web services' (e.g. web services that can be accessed and used through Internet-accessible public APIs) haven't really happened. When one looks at RSS aggregation sites such as it's quick to see that there are thousands of "web services" out there for people today.

In an earlier post Jeremy points to some recent thoughts on RSS published by Tim Bray where he outlines some the issues: growing bandwidth consumption, settling on a media-type and eventual demise of RSS aggregators as a standalone application class. He concludes:

...[RSS feed aggregation] just belongs in the browser. It will take a couple of years for it to get cooked into mainstream browsers in a mature enough form to be usable, so the guys with the RSS-reader software should make hay while the sun shines and start figuring out their Next Big Thing.

He also adds anyone who does any kind of publishing software had better start offering a real-easy-to-use RSS interface and sooner rather than later or they're just not going to be in the game.

I think gord says it best when he comments I am so impassioned by this recent explosion in open and well documented interfaces. We are so near a cascade level event with all of the emergent software that is evolving. And each new generation of software raises the potential interactions at an exponential rate. I concur and look forward to where this is all going.