What Is Web 2.0

O'Reilly's 2005 essay crystallized a set of patterns that were already emerging — network effects, data as competitive advantage, software as service, users as co-developers — and gave them a name that defined an era of web development. By contrasting Web 1.0 companies with their Web 2.0 successors (Britannica vs. Wikipedia, Ofoto vs. Flickr, publishing vs. participation), the essay made legible a shift from the web as a medium for documents to the web as a platform for applications and collective intelligence. Its influence was immediate and enormous: "Web 2.0" became the organizing concept for a generation of startups, investors, and technologists. Read today, it is both a historical document of a pivotal moment and a reminder of how much the platform dynamics O'Reilly described have since consolidated into the monopolies he did not fully anticipate. Still freely available on O'Reilly's site, it repays rereading.