Musings on Web 2.0 - Part 2
In my previous post on Web 2.0, I mentioned that one of the new trends in the web today is that of “mashups”. The idea is about getting data from multiple, disparate sources and collating them in interesting ways. For example, let’s say we need to create a mashup involving a map showing all theatres playing the highest rated (most popular) movie in a particular city. Now, to develop this, one would need several pieces of data from several sources. First of all, you need to use map services (like Google Earth or Virtual Earth) to show a map. Secondly, you need a service that lists all popular theatres in a particular city, and what they are currently showing. You would also need ratings and reviews for all the movies that are being screened. Today, all these pieces of information are currently available, but mostly in several different websites. Each of these web sites could have their own revenue model revolving around special services they provide (maybe reviews, for example). So, our mashup which we conceived earlier would receive a setback if there is no data/service available which provides that information in an easily consumable form. In other words, you need structured data to make magic happen.
HTML traditionally, has not been considered as structured data. Perhaps, that is why we have XML to represent complex data forms. But how do you represent information in XML for the web? One answer would be SOAP and Web Services. As revolutionary as web services are for business applications, I feel they are not that conducive to AJAX-based Web 2.0 applications of today. The reason is that SOAP isn’t simple anymore; or at least, for naïve JavaScript-based clients. The evolution of WS-* has morphed SOAP into a monstrous stack of composable standards, which is beyond the reach of simple scripting today.
So, the order of the day is XML, but in simpler formats, and which are accessible through simpler protocols. Perhaps, this is the reason why RSS and ATOM were born, and are very popular today. Perhaps, this is the reason why REST is gaining momentum. Today, we see a large ecosystem of applications built around RSS and REST, and this can be attributed to their simplicity.
While XML is really powerful, the inherent concern of web applications to incorporate XML to express semantics could seem to be additional investment in time and space. If we go a step backwards towards HTML, and look for ways of expressing semantics, we wouldn’t have an answer, right? Wrong. Apparently, HTML has certain attributes like rel, class, and rev that are rich enough to express, and at the same time could be decoupled from visual markup. This is the idea underpinning a new way of semantic expression on the web – Microformats. Microformats, like RSS, are creating a whole new ecosystem of standards and applications (like crawlers and bots) that make structured data even more pervasive and accessible.
Microformats are a Web 2.0 phenomenon, and are testimonial to what I had to say earlier – Web 2.0 has brought about new "innovative techniques" of harnessing existing technology stacks. Be it through XML or Microformats, hopefully, the World Wide Web will evolve into one large blob of structured data available for everyone to create mashups like never before!