Currently, there exist a large number of superb digital librari-es (DLs), all of which are, unfortunately, vertically integrated and all presenting a monolithic interface to their users. Ideally, a user would want to locate resources from a variety of digital libraries dealing only with one interface. A number of approa-ches to this interoperability issue exist including: defining a u-niversal protocol for all libraries to adhere to; or developing mechanisms to translate between protocols. (D-Lib, March 1999) The problem which the text point to is: