Jeffry Houser sent me an e-mail this weekend and asked me to define exactly what Web 2.0 is. I’ve spent a lot of time over the past week talking about Web 2.0, and it’s a fair question to define exactly what it is I’m so excited about. It’s also a very difficult question.

There seems to be a swelling backlash against “Web 2.0″ and I’m not really sure why. Joel Spolsky says

The term Web 2.0 particularly bugs me. It’s not a real concept. It has no meaning. It’s a big, vague, nebulous cloud of pure architectural nothingness. When people use the term Web 2.0, I always feel a little bit stupider for the rest of the day.

That’s a pretty resounding incitement from someone is well respected in the community. A look at this article over at The Register shows more examples of a big distaste for Web 2.0. I think all of this stems from an inability to really define what Web 2.0 is. Well let me do what I came here to do and define it for you: Web 2.0 is what the internet will be in 3-5 years.

Maybe that’s a bit of a trite definition, but in my mind, that’s the point and it’s why Web 2.0 is so exciting; we’re all still defining it. Tim O’Reilly has what seems to be the major definition, but every one of us is defining it every day when we contribute to the internet. I realize that’s kind of taking the easy way out, so let me draw from O’Reilly’s definition what I think are the most important aspects of Web 2.0.

To me, Web 2.0 is all about data, which really is what the web has always been about but there are a couple of important distinctions. What makes Web 2.0 different is that the data should be largely user created. Blogs, tags, reviews, comments, and wikis should all be huge components of Web 2.0. This makes the data more “human” which makes it more relevant to users and makes it easier to find what we’re looking for. Along those same lines, the data needs to be open. Developers should be able to use meaningful data in their own applications and extend others applications to continue driving the growth of the web.

The other big part of Web 2.0 is the idea of the web as a platform, and this is where RIAs come in. By leveraging the web as a platform, you can take advantage of the amazing ubiquity of it. Every OS can access the web, nearly every mobile device, even video game systems and TVs have some web capability. As developers, we now have the ability to reach an audience like never before. Imagine programming a great user experience that will work seamlessly and be accessible on a computer, a cell phone, and in a car. The web provides that possibility.

Not every Web 2.0 “application” is going to be an RIA, but if the data is presented in an accessible format, there isn’t any reason why Web 2.0 won’t be filled with RIAs that are providing extensive data with a fantastic user experience. I say again, I don’t necessarily think that Web 2.0 is synonymous with RIAs, but if you look at the principles of Web 2.0 that Tim O’Reilly espouses, RIAs are well positioned to provide the “face” of Web 2.0.

I realize this has been long winded, and I didn’t even really give you a definition of what Web 2.0 is, but I hope that you’re a little bit more excited about helping me define Web 2.0 and a little bit less cynical about using the term.