Web 2.0

XHR Requests as shown in Chrome Developer Tools

At some point in the early 2000s, a feature first introduced by Microsoft in 1999 called "XMLHTTPRequest" (XHR) was "discovered" by web developers. This coincided with the first wave of Javascript helper libraries designed to make Javascript easier to write and more modular so that Javascript features could be shared between projects. The combination of XHR and Javascript was branded "AJAX" (an acronym for "Asynchronous Javascript and XML"), and this became a buzzword of Web 2.0.

This situation formed the technological underpinnings of what became known as "Web 2.0." Commonly thought of as the "second generation of the web," that's not a bad way to summarize the era. The world was coming out of the initial shyness of the first big web bubble, and since many of the large players had been cut down in the crash there was plenty of room for new ventures to come online.

As broadband, always-on access became more prevalent, and the mass wave of notebook adoption began to take off, there was a corresponding shift in the way people thought about the online space. The obvious commercial efforts were exploited in the first wave of web growth: ecommerce and advertising became established and have continued to be significant drivers of web technology and culture. But the world of social interaction online was still not very textured.

The explosion of Web 2.0 is a perfect combination of technology and social need. Blogging services such as Blogger and MoveableType get their start in this time period, and the are bolstered by the ability to have content editing tools that felt more like a desktop app and were much less prone to data loss (thanks to the use of AJAX techniques).

Delicious.com circa 2006 Delicious.com, which began as del.icio.us, circa 2006

Web 2.0 brought the concept of "tagging" rather than "sorting" content -- applying one or more tags rather than organizing in nested folder hierarchies. This was made quick and efficient by, again, implementing AJAX tools to quickly edit tags on a site. And tagging opened the door for even better content search and find capabilities. Sites like Delicious and Flickr made big waves by successfully adopting the tagging paradigm and allowing users to tag content they created themselves.

Perhaps most importantly, Web 2.0 brought the notion that websites and web culture should be about participation to the masses. Web developers and content creators always knew there was a huge potential for the web to facilitate broad participation in culture and society. But the mainstream did not get to experience that reality until many more sites began experimenting with sharing and curating features.

All of these aspects of Web 2.0 made websites and web-based applications feel more and more like "real" applications found on the desktop of your computer. This newfound usability, and the creative possibilities unlocked by using Javascript in a much more significant way, pushed the web into a mainstream position where instead of playing supporting role to other forms of media or interaction, it became the primary, ubiquitous mechanism that all others would augment.