Like it or not, I don't think you can call any of those languages failures. Certainly not PHP, Python, or Ruby. I would venture to guess that all three are more commonly used than Lisp.

Failure in the Grahammian sense of being a dead-end.

"I think that, like species, languages will form evolutionary trees, with dead-ends branching off all over. We can see this happening already. Cobol, for all its sometime popularity, does not seem to have any intellectual descendants. It is an evolutionary dead-end-- a Neanderthal language." - http://www.paulgraham.com/hundred.html

Though I disagree with most of the conclusions in that essay, and in particular the expectation that Lisp (or a direct descendant) is going to be the language of the future, I still think it's way too early to call the above languages failures, even in the "Grahammiam" sense.

Python and Ruby especially are growing in popularity, and I think it's awfully premature to consider them evolutionary dead ends at this stage in the game.

I don't necessarily agree that those languages are dead either. I was just clarifying the point I thought he was trying to make. Plus I wanted to turn pg into an adjective :)

I mean failure like the tyrannosaurus rex. That is, from an an evolutionary perspective. Not at the arbitrary present. And I'd wager that Perl is still actually more used than Python or Ruby, it just doesn't get the love on social news sites and elite blogs.

I think Perl has been relegated to short scripts and legacy code bases. I don't see a lot of new projects being developed in Perl. That's what I meant by leaving it off the list.