This is the slide deck for the Google I/O 2012 "The Next Evolution of Chrome Apps" session. It itself is a Chrome packaged app. It currently runs in Chrome 22.0.1190.0 or later (as of 6/29/2012, this means canary channel only).
The session itself (including live demos) is available on YouTube.
The text editor used in the presentation is itself a Chrome packaged app. It's available in the samples repository.
The helloworld directory contains the "Hello World!" demo from the session, including the variant with the XSS issue (which can't be exploited due to CSP).
The diff-sample-files directory contains the two local files that were diff-ed during the offline diff tool demo (the diff tool itself is also available in the samples repository).
The servo directory contains the standalone version of the serial port API spinner demo. It only does writes to the serial port. The complete version in the samples repository has the full read/write implementation.
The windowing_api directory contains the source for the custom window frame and windowing API documentation (it's launched via the "Demo" link on slide 7).