Braintree Braintree is an e-commerce startup that processes payments – $5 billion annually – for more than 3,000 marketers including Fab.com, AirBnB, LivingSocial and Rovio's Angry Birds.



The company just moved offices into a new space in Chicago’s West Loop, and the new HQ is a doozy.

Sure, it features the usual startup suspects -- like a fully stocked kitchen, snack bar and an open-plan working area with all the beams and pillars exposed.

But the standout feature is the office's indoor treehouse, complete with hammocks and tree stumps.