: The European Distributed Institute of Taxonomy (EDIT) platform, as well as biodiversity providers in general, provides a multitude of web-based taxonomic applications and services. Also, the diversity of service providers reflects the highly distributed, cross-national organisational infrastructure of taxonomic institutions and collections. This results in a problem of identity management. While the provider's system administrators have to register users and maintain individual access control lists for each offered service, users have to remember a variety of login/password combinations to use all these different services. Therefore, EDIT promotes a Community Single Sign-On (CSSO) security infrastructure, which protects and provides access to all EDIT platform components based on a single identity per user. That way, users need to remember only one login/password combination to use EDIT's platform facilities. And, service providers can proceed to protect their resources and...