A year after the release of its Kindle iPhone application, Amazon has announced a beta version of Kindle reader for Mac OS X. The company also said an iPad app of its popular e-reader software is on the horizon, allowing Kindle subscribers to access their library on Apple's tablet.

With over 450,000 books, including most New York Times Bestsellers, Kindle is poised to compete head-on with Apple's own iPad application, iBooks. iBooks will provide access to the iBookstore, Apple's answer to the digital library concept. Other iPad reading apps are also on the way such as the Barnes and Noble eReader.