In the library world OPAC stand for On-line Patron Access Catalog, which is a fancy term for computerized card catalog. MPL will be updating our OPAC in the next few months and I have been doing some research on the topic. One of the more interesting article I found was How OPACs Suck by Karen Schneider. Though the title is rather blunt her article details features that are needed in future OPACs.
