In a likely response to Google’s book scanning project, Yahoo has announced that it will work with partners to make electronic versions of books available online. The project will be run by the new Open Content Alliance (OCA) and books will be hosted by the Internet Archive, a nonprofit group created to offer access to historical collections that exist in digital format.

Most news organizations are reporting that Yahoo is taking a more cautious step than Google by announcing that it will only scan and digitize texts in the public domain, except where the copyright holder has expressly given permission. However, this leaves open the question of what “in the public domain” actually means.

Google has come under fire for scanning all books and saying that it will release full texts of books with expired or non-claimed copyrights, while offering full searching through all texts. Publishers have been up in arms about this practice, but the legal community (or rather those not affiliated with a publishing house or the publishing industry) has said that this usage likely falls under “fair use”.

Yahoo may not be allowing the searching through full texts of copyrighted books (yet), but the scanning and offering of full texts for books “in the public domain” may match with Google’s announced plans. We will have to wait for the details to see how Yahoo defines this. If Yahoo begins scanning and offering books where the copyright holder is unknown, publishers across the board and the Authors Guild will have another target, and Google may have another ally.