The architecture of the AliEn system

To fulfil the above requirements, a new development cycle was triggered during which the AliEn Catalogue has been split into independent File and Metadata Catalogue Services, a Package Manager Service was created out of the former Package Manager Component and a Grid Access Service was developed in compliance with the EGEE security model.AliEn (ALICE Environment) is a Grid framework developed by the Alice Collaboration and used in production for more than 3 years.This paper presents the architecture of selected components of the AliEn system and describes its evolution in context of the EGEE * project.