BUG is a modular, open source system for building devices.

calibre has a modular device driver design that makes adding support for different e-reader devices easy. At the moment, it has support for the SONY PRS 500/505/700, Cybook Gen 3, Amazon Kindle (1 and 2) and the iPhone (with the stanza reader software). Syncing supports updating metadata on the device from metadata in the library and the creation of collections on the device based on the tags defined in the library view. If an book has more than one format available, calibre automatically chooses the best format when uploading to the device.

"PhoneGap is a free open source development tool and framework that allows web developers to take advantage of the powerful features in the iPhone SDK from HTML and JavaScript. We're trying to make iPhone app development easy and open. For many applications a web application is the way to but in Safari you don't get access to the native iPhone APIs, and the that's the problem we're trying to solve."

A Wired article talking the importance of Chrome.