**5.8 Concluding remarks**

AliEn is a high-level middleware adopted by the ALICE experiment, which has been used and validated in massive Monte Carlo events production since 2001, in end-user analysis since 2005 and during the real data management and processing since 2007. Its capabilities comply with the requirements of the ALICE computing model. In addition to modules needed to build a fully functional Grid, AliEn provides interfaces to other Grid implementations enabling the true Grid interoperability. The AliEn development will be ongoing in the coming years following the architectural path chosen at the start and more modules and functionalities are envisaged to be delivered.

The Grid (AliEn/gLite/other) services are many and quite complex. Nonetheless, they are working together, allowing to manage thousands of CPUs and PBs of various storage types. The ALICE choice of single Grid Catalogue, single Task Queue with internal prioritization and a single storage access protocol (xrootd) has been beneficial from user and Grid management viewpoint.
