The O'Reilly network has a new piece for all of those sceptics out there that believe the myth that "Java scales and PHP doesn't". The PHP Scalability Myth explains just how scalable PHP really is...

PHP scales. There, I said it. The word on the street is that "Java scales and PHP doesn't." The word on the street is wrong, and PHP needs someone to stand up and tell the truth: that it does scale. [...] Those with a closed mind can head straight to the inevitable flame war located at the end of this article. Those with an open mind who are interested in taking their web development skills and putting them to use building applications in the cross-platform, easy-to-write, easy-to-maintain, scalable, and robust PHP platform, but were hesitant because of the scalability myth, should read on.

The author goes on to talk about what scalability really is, and compares the architecture of Java versus PHP in how they handle it. Then, moving into a bit thinner ice, he talks about the link between Java and PHP and the "Java scales and scripting languages don't" statement. It's an interesting read...