What Programing Language Are the Largest Websites Written In?

I don't remember how, but today i suddenly got reminded that Facebook is written in PHP. So, on the spur of the moment, i tweeted:

Remember folks, the world's largest sites {Facebook, Wikipedia, “Yahoo!”, etc} are written in Pretty Home Page!

and followed with:

To Chinese friends, what's Baido, QQ, Taobao, Sina written in?

Then, this question piqued me, even i knew that i should never waste my time with such a trifle. But before i can resist, i already spent 20 min to write this list (with help of Google):

The numbers are the site's rankings, from alexa.com. (missing ones are mostly duplicates, such as google japan, google india, etc.)

It's quite notable that twitter stands out with Scala and Ruby.

Those with perl are probably going back to the first dot com era (aka Web 1.0, ≈1995 to ≈2002). At that time, perl was basically the only game in town (secondarily: Java). (i don't recall what amazon and ebay were in… was it perl or php? how about imdb.com?)

most php follows starting in early 2000s, that's when PHP quietly surpassed perl in all battle fronts.

it'd be interesting to know what some of the chinese sites uses, and porn sites (⁖ livejasmin, xvideos, youporn)

as for Microsoft sites… i suppose they are ASP for older sites and C# with “.NET” for new?

Fill in the blanks please.

thanks to roowe, krfantasy