Appropedia.org, which describes itself as “the site for collaborative solutions in sustainability, poverty reduction and international development,” has made available, in cooperation with Google, a beta version of a “public domain search engine.” The purpose, of course, is to help people find public domain material that they can use freely, without having to worry about copyright restrictions. Since such material can provide source for education, creativity and economic development, this project fits well into the self-defined mission of Appropedia.
It appears that the search engine focuses primarily on U.S. government material, which is in the public domain from the moment it is created. They have a nice explanation here of how they have gotten to the point of beta launch and where they hope to go. While this is a good start, there is a wealth of public domain material beyond the reach of this plan. Like the Google book search, this project is limited by the difficulty and expense of discovering what is and is not in the public domain. Ironically, while this search engine focuses on federal government materials, the Google Book project treats most government material as copyrighted works, since its definition of the public domain is limited to material published before 1923. Both definitions are radically narrow, and they emphasize the need to revise our copyright law to make the many works that are likely in the public domain (many so-called Orphan Works never had their copyright renewed, for example) easier and safer for the public to use.
In the meantime, however, this search engine, along with the more robust ability to search for material licensed under the Creative Commons licenses, offer great tools for helping scholars, teachers and others escape the straitjacket of our overly restrictive copyright law.