The prototyping half includes some heavy-duty equipment that you'd be more likely to see in a factory than an internet veteran's campus. It touts lathes, milling machines, water jets and other devices that can cut or shape everything from metal to stone. There's also a CT scanner and an electron microscope to detect miniscule flaws.

A lab like this was really just a matter of time, since Facebook only has so much room to develop hardware in its existing facilities without looking for outside help. Still, it's a telltale sign of how much the company has changed. The days of Facebook focusing strictly on social services are long gone -- this is a general tech company where physical products are equally important to its future.