The DELOS network will carry out a broad range of interrelated activities whose combined effect should be to contribute to the successful achievement of the objectives as defined in Section 2. In particular, important objectives of the Joint Programme of Activities for the first months will be: - Tightening up the Network. The first 18 month period is critical and much effort will be dedicated to constructing a sound community sense between the network members. - Putting up the infrastructure. Because of its importance, we also plan to devote considerable energy to the building of an intranet portal, together with a publicly accessible web site, equipped with the appropriate services and communication tools for the all activities.

The plan for the Joint Programme of Activities defines the start and end of a subset of the activities presented in section 6. These activities are organized into clusters and are composed of three types of activities: integrating, research and dissemination activities. They have been assigned a schedule, both in terms of time and participating institutes and they favour the creation of the network community and emergence of multi-lateral collaborations. Each cluster is structured according to the Workpackage-Task hierarchy.

In addition, there are the activities for the management of the Network, which also have been structured according to the Workpackage-Task hierarchy. The Network is thus composed of the following Workpackages for the first 18 months:

Information architectures for digital libraries are now evolving in parallel with architectures for peer-to-peer (P2P) systems, Grid-enabled environments and institutional repositories. In some cases, developments have proceeded in a fragmented way perhaps on a local basis (within an organization), in particular domains and sectors (within museums, libraries and archives) and within disciplinary boundaries (in bio-medicine or the performing arts). Synergies between initiatives are becoming apparent both at the technical level and in terms of the broad operating principles being adopted by the parties involved.

For example, many of these developing architectures are predominantly service-oriented; they are adopting emerging Web Services standards and are becoming increasingly user-focused in their presentation. A main contribution of this workpackage will be to facilitate the development and integration of building blocks for digital libraries. This requires both the identification and specification of service interfaces and the definition of a generic.

We can distinguish three different approaches to DL architectures. The first is the (Web) service architecture (SA) and includes the related standards for describing, finding and invoking services. The SA leads to a new way of building distributed information systems, specifically DLs. Many applications do not need complete answers or fully fresh data.

This brought up new distributed data management concepts subsumed under distributed Peer-to-Peer (P2P) data management. In parallel to this approaches a third direction, the Grid computing evolved and the associated Open Grid Service Architecture (OGSA)1 is leading to the development of increasingly complex computer systems. These Grid architectures show high potential for the management, discovery, and loadbalanced use of distributed digital library services, together with application-specific security aspects. Grid-enabled environments with distributed processing capabilities, the utilization of remote resources and dynamic online experimentation have encouraged the consideration of new approaches to information system management.