Annotea was developed as a Web-based shared annotation system based on a general-purpose open RDF infrastructure where annotations are modeled as a class of metadata. Annotations, identified by a URI, are viewed as statements or remarks made by an author about a Web document. In the Annotea model (see figure 1), the context defines where exactly inside the document the annotation is attached and the body is a link to the content of the annotation identified by a URI and conceived to contain textual or graphical content. Annotations are external to the documents and can be stored in one or more annotation servers that are responsible for controlling access - this allows us to implement local/private and remote/shared annotations.
CHICAGO -- For a stranger, the main library at the University of Illinois at Chicago can be hard to find. The directions I got from a pair of clerks at the credit union in the student center have proven unreliable. I now find myself adrift among ash trees and drab geometric buildings.Finally, I call for help. Firouzeh Logan, a reference librarian here, soon appears and guides me where I need to go. Several unmarked pathways and an escalator ride later, I am in a private room on the second floor of the library, surrounded by librarians eager to answer my questions.