Setup costs - PHP has a low barrier to entry in the sense that Apache's mod_php5 is a simple "a2enmod php5" command away. Even PHP-FPM with Nginx is only a few

Setup costs - PHP has a low barrier to entry in the sense that Apache's mod_php5 is a simple "a2enmod php5" command away. Even PHP-FPM with Nginx is only a few well-documented configuration options away from working. Currently, no other language can match that. They either require a VM running (Java, Ruby, etc.) or at least have a compile/build step (Python). UWSGI has a lot of promise, but until it's as easy to get configured as PHP-FPM, PHP is still way easier than everything else.