While definitions vary somewhat, people who talk about Web2 generally seem to be in agreement about several core facets:
- It's XML-based, rather than HTML based.
- It's based upon the notion of open and public standards. Web2 is, for the most part, built upon the W3C stack.
- It places more importance on a robust client that can work with a variety of different XML-based languages, such as SVG, XHTML, RSS, DocBook, and so forth. Features of a browser are less important than the degree to which the browser adheres to these standards.
- It is largely indifferent to desktop or server operating systems, though open source server technologies seem to be gaining ascendancy over proprietary ones
- It permits for much more robust intercommunication between client and server, and tends to stress the notion that intermediate state is maintained not specifically on the server, but rather at the point where the statefulness is most needed. (AJAX will likely play a big part in this).
- It is, for the most part, REST-based, though it utilizes message based architectures (such as SOAP) where they are appropriate
- It extends beyond the concept of "web pages" and into dynamic applications (and even desktops) that can be updated in real time based upon streaming XML.