[lucaspiller]

WhatsApp had over 2 million users connected to their (Erlang) server last year.

http://blog.whatsapp.com/index.php/2012/01/1-million-is-so-2...

Here is the same in Erlang for reference (from a few years ago, I would be interested to see if there is a more efficient way now):

http://www.metabrew.com/article/a-million-user-comet-applica...

[e12e]

Thank you so much for that last link especially. Interesting stuff :-)