It remains however a laborious undertaking to consult several library catalogues in search of an item.
Searches have to be repeated, using the proprietary web-interface of each catalogue.
This means that a user is only confronted with one interface while searching databases mounted on different systems. On top of that, these databases can be searched simultaneously. Most of these systems support the Z39.50 library access protocol and libraries are investing resources in making their catalogues available through this standard. As said before, the standard allows for simultaneous consultation of catalogues, a facility that previously could only be obtained by physically joining the catalogue records into one union catalogue. The Antilope catalogue is maintained by the library of the Antwerp University through continuous updating based on the changes reported by the participating libraries.