Many folks are working towards getting at the heart of the Web 2.0 revolution. I agree that visualizations such as Tim O'Reilly's or Dion Hinchcliffe's are not simple enough ? they're too jargon-filled and don't do much to describe the big picture in human-readable terms. I really like Richard MacManus's breakdown: "Web 2.0 is really about normal everyday people using the Web and creating things on it - forget the acronyms." Susan Mernit also captures this well: "The heart of Web 2.0 is the user... The tools power it, but the people do it."

I'm also going to throw in some of my own ideas into this asymptotic approximation of the curious wonder that is Web 2.0: visualization, ho!

From personalization to glocalization and back again

I think the most interesting aspects of Web 2.0 are new tools that explore the continuum between the personal and the social, and tools that are endowed with a certain flexibility and modularity which enables collaborative remixability — a transformative process in which the information and media we've organized and shared can be recombined and built on to create new forms, concepts, ideas, mashups and services.

The diagram above places some technologies closer to the personalization end of the spectrum, some far towards the social or glocalized end, as well as placing a sizeable number of technologies that fall somewhere in the middle of the continuum that in large part enable and promote both personalization and danah boyd's concept of glocalization. Collaborative remixability encompasses all of these systems as well as including technologies that exist specifically to promote the recombination of building blocks both large and small.

One of the early lessons that pioneering Web 2.0 services like del.icio.us and Flickr taught us is that information that we organize well for ourselves has a very happy serendipitous side effect, in that it also tends to make that information more useful to other people. The tools of Web 2.0 exist in this interplay between information we organize for ourselves and that which we share with others. We also figured out that the differing ways in which folks tends to organize information need not always be mutually exclusive — this is the advantage of folksonomy over classical hierarchical ontologies (though even folksonomy and hierarchy need not be mutually exclusive). Individuals and groups can organize information in local contexts that make sense to them, without precluding other individuals and groups from doing the same within their own domains, and this works because the "space" we have available for organizing in the digital domain is unbounded. As Shirky says, there is no shelf — no physical constraint which prevents us from categorizing and presenting information in multiple simultaneous ways (though I disagree with Clay that this will (or should) lead to a consistent collective ontology. I think the whole point is that we no longer have to be globally consistent — we can have our multiple culturally relative frameworks, non-mutually exclusively).

From what we already know to what we most need to discover

There is another axis which relates to the individual - social axis and to Web 2.0, which is the continuum between what is familiar and what we already know, and discovery, or that which is serendipitous. The new tools of Web 2.0 explore the continuum here, too — we use YASNs to articulate the social networks we've already established as well as to make new connections; we use social bookmarking to store information but also to discover new information via related channels and interests; we use media recommendation engines to discover new artists and works based on the things we already know we like.

I've mapped out a subset of sites, services and technologies onto the two axes of individual - social and familiar - serendipity below. Of note with this diagram is that the various services don't truly exist as points but have their own ranges over which they operate — and depending on how an individual user makes use of the tools, we may interpret where they fall on the axes somewhat differently (and that's okay! Heck, that's great!).

Web 2.0 themes and memes

There are also a few overarching Web 2.0 themes that warrant further discussion:

• Inversion of control
• Efficiency and portability of information and services
• Remixability and innovation

Robert Young elucidates this concept rather well. There is a tension between business and community, and Web 2.0 is pulling hard towards inverting traditional power structures downwards. Companies create the code and the frameworks, but more and more, users are creating the content, the culture, the true value of the systems they inhabit. Wise companies will realize they must be extremely proactive about sharing power and control with their users, because real people investing real time and energy have real emotions, and when angered by perceived loss of control will quite simply take their time and energy elsewhere, leaving empty, valueless code and frameworks — no matter how "functional" or "useful" they may appear in an objective sense. Wise companies will also realize that innovation need not come only from within the walls of the corporation, but will also be coming in droves from their users.

The culture of hackability and DIY is part of this inversion of control. We're moving away from the days of "one size fits all" and monolithic tools developed to try and please everyone, into an era of user-centric, user-configurable tools — because the tools we're now using have an architecture of flexibility that allows hyper-customization at the individual level. The long tail is another manifestation of the inversion of control, in which a coalition of small markets is starting to wield a level of control comparable to popularity, hit-driven markets. The rise of the Creative Commons and challenges to intellectual property and copyright are also about the inversion of control, in which individuals and groups are bypassing traditional media rhetoric of ownership and control and creating our own culture in which media has more value, not less, when remixed and recombined. This is successful because the internet has democratized methods of distribution, and we need not wait for "culture" to be handed down from on high by broadcast media. We create culture; we are culture.

Efficiency and portability of information and services

As more and more of us become responsible for sifting through massive amounts of information and content, we are realizing the value inherent in making that information portable, flexible, and reusable. We no longer have time to labor over presenting information in different ways for different contexts, and the technology of open web standards has enabled a far easier repurposing of information. Here's the beauty of RSS — publish once, syndicate anywhere: to a newsreader, to another site, to a portable device. Why duplicate effort? And here's the beauty of AJAX and the rich UI experience — why walk through a series of steps when you can just click and edit? Why click through to another page to see related information when it can appear in a hover over? We don't have even time to click anymore, and it's only going to get worse.

This drive towards efficiency operates on both the personal, individual user levels as well as the social, glocal levels — users are tired of inefficient and cumbersome conversion processes to move data from one device to the next, and those movements are only going to increase as the number of portable devices continues to proliferate, as computers take up residence in living rooms, and as we move ever deeper into an always-on, interconnected world of ubiquitous computing. Groups are tired of inefficient and cumbersome methods of porting data and collaborating on documents, applications, services, projects. Open standards enable a far more seamless experience of data portability, and companies across all electronic domains would do well to move away from walled gardens and closed formats with all due haste, because they won't survive the transition to the intertwingled world of Web 2.0.

Remixability and innovation

This is the primary key of Web 2.0. The flexibility and modularity of the building blocks of Web 2.0 are lowering the barriers of participation drastically. As more and more people can play while needing less and less knowledge of the technical underpinnings of the tools, the potential for radical innovation increases enormously. Developers are wonderful individuals, but they build tools with developer's mind. Non-developers are beginners who work with beginner's mind. You get wildly new and different results when people combine things with beginner's mind. You get fascinating new tools and mashups that developers would never have dreamed of. This is not to slander developers — this is to celebrate the less technical individuals that Web 2.0 is starting to reach out to. Open APIs and web services are a great first step — but imagine when building web applications becomes as simple as playing with LEGOs. Imagine what the web will look like when your kids can easily glue together web services to make beautiful, unexpected, useful things — for themselves, for (and with) your family, for (and with) their friends, for (and with) their communities. That is what gleams on the horizon of Web 2.0.