Everyone's doing it -- the poster children for "Web 2.0" are built on top of the LAMP stack. The next generation of web-based applications are built with free tools, with few people understanding the best way to scale these applications out. But patterns emerged very early on -- all of these applications share some common architectural principles that seem to be working. In this brief state-of-the-world, we'll look at the various approaches to scalable internet application architectures and what we can learn from them.