After having preached the gospel according to peopleware on many occasions, Joel has put his money where his mouth is and setup the perfect developer environment at his new office. This is the kind of office where I'd like to work.
I am not sure I agree with his bottom line though:
The monthly rent for our offices, when fully occupied, will run about $700 per employee. The build-out was done on budget and paid for almost entirely by the landlord. I suspect that $700 per person is on the high side for software developers throughout the world, but if it means we can hire from the 99.9 percentile instead of the 99 percentile, it'll be worth it.
Hiring only from the 90 percentile is extremely difficult (though this entry gives me the impression that Joel may have a fairly good shot at it) - but 99 or even 99.9 percentile? I don't think that's an attainable goal. I do believe he'll get his money's worth though - but IMHO the payout will be in increased productivity and job satisfaction (leading to reduced turnover) instead.