In what can be seen as a strike against Amazon's Kindle electronic book reader, Google has announced it will make more than half a million public domain books from its digitization project available for free Sony's eBook store. The move gives Sony customers more than 600,000 titles in the open ePub format to choose from and puts some pressure on the much-hyped Amazon Kindle, whose library totals 245,000 books and only supports the proprietary AZW format or unprotected .mobi books.

Amazon has mentioned it is open to more formats but, for the time being, the Kindle even lacks proper support for the PDF format - it is possible to convert these files to AZW but for a fee. Google was also quick to emphasize the need for openness in the eBook market and said the partnership with Sony is not exclusive.