Add support for Square payment processor
Square has been around for a while now and they've added an API so they can be integrated into commerce systems. BigCommerce is one of the big ecommerce players that is already providing Square as a processor.
It is natively PCI compliant.
Square is good for many merchants as well as they were the first to provide a card reader that plugs into mobile phones (brilliant). But the nice thing about them that will appeal to many of us is their flat rate structure which is simple to understand and may well be less expensive than other options.