Abstract: Phaidra (Permanent Hosting, Archiving and Indexing of Digital Resources and Assets) is used as a long-term preservation system through the assignment of persistent identifiers (permanent links). The project was launched in 2006 and is the successful result of cooperation between the Vienna University Computer Center, the Center for Teaching and Learning and the Vienna University Library. At present, Phaidra contains about 60,000 objects, all of which are provided with structured metadata.