Friendster has switched from Java to PHP, with flamage following. Why PHP Scales - A Cranky, Snarky Answer is surprisingly level-headed, and more language neutral than the response's title suggests. Both are worth skimming; the first to set up the all-too-familar pattern of "If you couldn't make X work with my favorite technology, then you're no good," "Yes we are, we had experts," "No you aren't/your experts are not good," blah blah blah; the second for a bit sanity.
The phrase "not scalable" is quickly becoming a lame argument against a programming language in the way that "unintuitive" is a lame argument against a windowing system. It usually means absolutely nothing and betrays a smug sense of self-satisfaction that really ought to stay private.
I miss the days when people argued against indenting because fewer tokens meant faster compiles. Now it's slightly less obvious which people never to take seriously again.
I agree with George's assessment. The bottlenecks are never the language - it's the SQL, or the algorithm, or the network.
