The EGEE infrastructure is based on a Grid Middleware stack called gLite, which is integrated, certified and distributed by the project itself.

A large fraction of the services included in the gLite distribution are maintained and further enhanced by the Middleware Engineering Activity, whose goal is to provide a reference open source implementation of selected Grid services satisfying the requirements of both users and administrators, in terms of functionality, performance and manageability.

The available services in the gLite distribution can be broadly classified in two categories:

• Grid Foundation Middleware, covering the security infrastructure, information, monitoring and accounting systems, access to computing and storage resources, providing the basis for a consistent and dependable production infrastructure;

• Higher-level Grid Middleware, including services for job management, data catalogs and data replication, providing applications withend-to-end solutions.

In order to favour interoperability with other Grid infrastructures, the interfaces of the services are, wherever possible, compliant with established standards, primarily defined by the Open Grid Forum. With its experience in developing production strength services, EGEE is also committed to contribute to the standardization process through the OGF-Europe project.