[doubleplusgood]

As originally built by him, it was indeed just a php website.

[samblr]

>> it was indeed just a php website.

How quickly can one build and how quickly can it scale ? - Speed is the name of the game - is it not this rule which holds true when building things on internet.

Or else, most of top internet apps are just going to be php,rails,node web-apps

[UK-AL]

The point is once it started to get to medium and large scale, there was experienced developers scaling it instead of zuckerberg.

[roryisok]

This was my original thought. Zuckerberg hired people to scale facebook to what it has become today.