YouTube is developed on PHP or .NET ?

[decobars]

I really need to know if YouTube is developed on PHP or .NET ?
and what about Facebook ?
Thanks in advance.

[jonathanlks]

YouTube is developed on ASP.NET
Facebook is developed on a combination of PHP, Perl, Python, C++ and Java though it's primarily PHP

[indetine2]

I am not sure about YouTube but facebook is PHP. If I would have to guess on YouTube it's also PHP. I think PHP is the most widely used scripting language.

[Pekoe200]

Youtube was developed using python (mostly).

Facebook was developed using php for the front end, and tomcat/java for the backend.

[sk89q]

I built a YouTube Flash player back in the day when YouTube was all new (it was a really badly designed player to embed back then). All their URLs ended in .php. Some months later after I started this player, YouTube gradually removed the .php extensions, removing the .php extension off the internal things last (i.e. the ones that loaded the movie). Though, even now, look: http://www.youtube.com/watch.php?v=nsCXZczTQXo - I would presume YouTube's frontend is largely written in PHP then, *unless* they really rewrote all their code, doubtfully. The backend stuff is not in PHP though, I hear. It is written in Python.

Facebook is largely in PHP.