PANGAEA - Publishing Network for Geoscientific and Environmental Data (http://www.pangaea.de) is a unique information system which is operated as an Open Access library for georeferenced data from basic research on earth and environment. Data are archived with related meta-information following ISO19115 standards in a relational database. Data are distributed via webservices with OAI protocol in XML-format e.g. to serve portals. Data are also accessible through various clients and a search engine on the Internet. Data set descriptions include a bibliographic citation and are persistently identified using Digital Object Identifier (DOI); the citation with DOI is mirrored to public library catalogs. The system provides data from institutes and international projects, covering all fields of earth system research with a main focus on the marine environment.