P. Buncic (CERN)
AliEn (ALICE Environment) is a Grid framework developed by the Alice Collaboration and used in production for almost 3 years. From the beginning, the system was constructed using Web Services and standard network protocols and Open Source components. The main thrust of the development was on the design and implementation of an open and modular architecture. A large part of the component came from state-of-the- art modules available in the Open Source domain. Thus, in a very short time, the ALICE experiment had a prototype Grid that, while constantly evolving, has allowed large distributed simulation and reconstruction vital to the design of the experiment hardware and software to be performed with very limited manpower. This proved to be the correct path to which many Grid project and initiatives are now converging. The architecture of AliEn inspired the ARDA report and subsequently AliEn provided the foundation of components for the first EGEE prototype. This talk presents the architecture of the original AliEn system, describes its evolution. A critical review of the major technology choices, their implementation and the development process is also presented.