Abstract: An electronic book distribution system includes electronic devices that reset their passcodes after specified authentication failures. The passcodes of an individual electronic device is reset to a value that is generated using a predefined function of a randomly generated support code. The support code is displayed to the user, and the user is instructed to contact a support service in order to obtain the new passcode. The support service independently authenticates the user, calculates the new device passcode using the same predefined function used by the electronic device, and provides the new passcode to the user.

Abstract: A machine-readable code rendering device may include an electronic paper display and a machine-readable code rendering module that dynamically renders machine-readable codes on the electronic paper display. The electronic paper display may be configured so that the machine-readable codes are read by a light-based code reader off of the electronic paper display.

Abstract: An electronic book distribution system includes electronic devices that reset their passcodes after specified authentication failures. The passcodes of an individual electronic device is reset to a value that is generated using a predefined function of a randomly generated support code. The support code is displayed to the user, and the user is instructed to contact a support service in order to obtain the new passcode. The support service independently authenticates the user, calculates the new device passcode using the same predefined function used by the electronic device, and provides the new passcode to the user.

Abstract: An electronic book distribution system includes electronic devices that reset their passcodes after specified authentication failures. The passcodes of an individual electronic device is reset to a value that is generated using a predefined function of a randomly generated support code. The support code is displayed to the user, and the user is instructed to contact a support service in order to obtain the new passcode. The support service independently authenticates the user, calculates the new device passcode using the same predefined function used by the electronic device, and provides the new passcode to the user.

Abstract: A sharing service receives a request to store a media item stored on an electronic book reader device for sharing with one or more other content rendering devices. In response, the sharing service associates a pass phrase with the request. The sharing service then provides the media item to those devices (e.g., eBook reader devices) that provide the pass phrase to the sharing service within a predetermined amount of time.

Abstract: A machine-readable code rendering device may include an electronic paper display and a machine-readable code rendering module that dynamically renders machine-readable codes on the electronic paper display. The electronic paper display may be configured so that the machine-readable codes are read by a light-based code reader off of the electronic paper display.

Abstract: A windowing system for an electronic device that uses an electronic paper display may include a compositor, a frame buffer, and a display controller manager. One or more applications running on the electronic device may request multiple changes to windows. The compositor may determine multiple update areas, where an update area indicates the smallest area of the electronic paper display that should be updated as a result of changes being made to a window. The update areas may be stored in the frame buffer. The display controller manager may create a cumulative update area based on the update areas that are determined between a begin update instruction and an end update instruction. The display controller manager may instruct a display controller to update only the portion of the display corresponding to the cumulative update area.

Abstract: A sharing service receives a request to store a media item stored on an electronic book reader device for sharing with one or more other content rendering devices. In response, the sharing service associates a pass phrase with the request. The sharing service then provides the media item to those devices (e.g., eBook reader devices) that provide the pass phrase to the sharing service within a predetermined amount of time.

Abstract: Tools and techniques for creating presentations via dynamic digital content (DDC) tools using a display dependent markup language interface facilitating dynamic content are described. The markup language, “DXyml”, identifies content elements, including dynamic content elements, for display and specifies pixel locations at which to position the content elements on a client device. Pixel locations are selected for particular screen configurations, allowing the presentations to be created in advance of being served to specific types of devices with the particular screen configurations.