[fennecfoxen]

I'm a little surprised that HHVM would make or break anyone's decision to use PHP, since I'd think that there are more important language design concerns and features that ought to figure before it came down to that... at least in a PHP-vs-Java sort of fight, anyway. Big questions like your preferred form of typing (strong/weak, dynamic/static/Hindley-Miller inference, etc), threading, ease of writing list comprehensions, whether you need to have functions as first-class objects, et cetera et cetera. Or the ability to hire developers who use that language.

[jszymborski]

For me I guess it's choosing the right weapon for the right enemy. If my greatest priority is shipping something tomorrow, I'll choose PHP or Python because I can code that in a blink.

However, if I'm able to hang back and take some time to develop something, priorities like being able to handle X I/O writes or, as you point out, threading becomes more relevant.