The PHP Scalability Myth: A well-reasoned and well-written argument for the scalability of PHP as opposed to Java. The theory is that even though Java may be faster to execute, J2EE has so many layers and abstractions that the end result is about the same. PHP is less architected, and therefore has less overhead (heck of a lot easier to program, too).
“I’m sure that what I have said in this article will be picked to death and ridiculed by some. I stand by what I have said. The idea that PHP does not scale is clearly false at the performance level. In fact, we should have never even gotten to the point where this article was necessary, because as engineers, we should recognize that the argument that one language clearly ‘scales better’ than another is, on its face, ridiculous. As engineers and architects, we need to look objectively at technologies and use a factual and rational basis to make technology decisions.”