In june, a first edition of Galileo's 1610 Sidereus Nuncius fetched more than $380,000 at a Christie's auction. The amount surprised observers who were shocked that even an eager collector with deep pockets might pay that kind of money for the historical manuscript. What is even more surprising is that booksellers Patrick Ames and John Warnock are offering the same volume for $25. And buyers won't have to worry about breaking bindings or tearing delicate pages, because the rare books Ames and Warnock sell are digital.

Warnock, co-founder and CEO of desktop-publishing-software firm Adobe Systems, and Ames, former publisher of Adobe Press, the company's book-publishing arm, joined forces several years ago to find a digital means of capturing rare books and manuscripts. Warnock keeps an extensive private library, so the partners first aimed their digital cameras at his 350-year-old collection of Shakespeare's sonnets, creating high-resolution images of the pocket-sized volume. They used Adobe Acrobat software to build an interface with the electronic archive that allows a user on almost any personal computer to "page through" the Bard's book, zooming in to read the text or examine the aged paper.