One of the open problems of the global information society is to ensure the long-term accessibility of digital documents. kopal tackles this problem head-on: In a three-year project, financially supported by the Federal Ministry of Education and Research, kopal's objective is the practical testing and implementation of a cooperatively created and run long-term archival system for digital resources. The solution is based on DIAS (Digital Information and Archiving System), jointly devised by IBM and the National Library of The Netherlands in The Hague, and will be adopted to the project needs with several extensions. The system will be implemented in accordance with international standards for long-term archiving and metadata within the OAIS framework (Open Archival Information System). The project partners, Die Deutsche Bibliothek (DDB), Göttingen State and University Library (SUB Göttingen), IBM Deutschland GmbH and the Gesellschaft für wissenschaftliche Datenverarbeitung mbH Göttingen (GWDG), will establish a cooperatively reusable solution for cultural heritage institutions, as well as for business and industry. Additionally, the project partners DDB and SUB Göttingen develop within the project a software for the input and the access of data, which will be released under an open-source license.