PHP as your secret sauce? 
vdibart: Ooo, this is total flame war bait.....You're making a lot of assumptions about what a "modern" language is here, but I wont' dwell on that : )  Suffice it to say you should give PHP another look, particularly in the context of some of the PHP frameworks that are popular these days (e.g. CodeIgniter, Zend, CakePHP, etc.)I develop in Java for my full-time job and develop in PHP for my side projects.  I enjoy PHP much more than Java.  It's a tool, and as with every tool you need to understand how to use it effectively.  Some people don't have the mindset that makes this possible, but for those that are willing to let their instincts take over (as opposed to the compiler) can find PHP to be very productive.  That being said, I can't for the life of me understand how something as big as Facebook can be done in PHP, but I'm willing to assume those guys are smarter than I am.