OPUS

DSS's OPUS database and cataloguing utility was designed and developed, and is maintained in-house by DSS staff and runs in a mini-mainframe environment.
OPUS contains in excess of 13,000,000 MARC records and currently consists of the complete Library of Congress (LC) database, the National Library of Canada (NLC) database, DSS's own UNIQ file, as well as DSS customer union databases which are housed and maintained by DSS. DSS's UNIQ file contains records that have been created through current cataloguing or through retrospective conversion (RECON) for DSS customers which were not in the source files.
DSS is a full subscriber to the MARC record distribution services of the national source agencies. Since MARC data files are downloaded via FTP on a weekly basis, the OPUS database is a more current source for bibliographic data than are CD-ROM sources.