The World Digital Library is a project that is quite vast in scope, but is looking ready to take on the challenge of combining primary historical resources from many of the worlds great libraries.
This project was started by UNESCO and the U.S. Library of Congress just last year, and was the subject of a presentation at the Free and Open Source Software for Geospatial (FOSS4G) 2007 conference last month.
Using PostGIS and MapServer, open-source programs that together join a database with mapping information, the library will allow users to search for and retrieve information via a well-thought-out, multi-lingual, world map interface, with a variety of tools for narrowing the search parameters.
I say “will allow users to search” because the library is not yet live. They do, however, have a demonstration video available, in two sizes:
There is also a good article about the project in the Washington Post.
found on One Big Library