[smokinn]

Ask yourself this: would the Instagram team have been as successful had they chosen PHP? I think not.

Why not? You do realize the "team", facebook, that acquired them (worth many multiples of them at the time of acquisition) is a PHP-based company right?

[gbog]

The interesting thing to ask should be if Facebook or Wikipedia's engineers would use PHP if they had to start from scratch. I used PHP for a big project before for legacy reasons but I wouldn't choose it for anything new even with a machine gun pointed to my manly parts. Neither would I use Java or VB for that matter.

[dpritchett]

Facebook and Wikipedia (and Wordpress) were born outside the software engineering establishment using lowest common denominator tools [1]. There's a reason for that: LAMP/WAMP has an extremely lower barrier to entry. A billion monkeys banging away on typewriters can make world-beating products, even if they don't compare to the works of Shakespeare in terms of literary quality.

Once these products prove themselves in the market then "professionals" are brought in to handle them, and these people probably know and like more refined tools such as Python or Java or something. It doesn't matter what language these new caretakers would choose for a rewrite though; PHP gave their system its first breath and that's how it stays long past the point in the lifecycle where PHP is a competitive advantage.

[1] http://en.wikipedia.org/wiki/MediaWiki#History

[prodigal_erik]

Pretty sure they would agree. The Quora and Asana founders seized on the opportunity to leave it behind, and what I've heard from Facebook staff is that they've managed to live with PHP. I can't remember anyone saying they like it.

http://www.quora.com/Quora-Infrastructure/Why-did-Quora-choo...

[cageface]

Our main takeaway from that experience is that programming language choice is very important and is extremely costly to change.

Taken directly from the horse's mouth, handwavy arguments about languages making no difference to the contrary.