Grid infrastructure is composed by middleware services which integrate computational and storage resources, sensors, scientific instruments and databases, by creating a distributed environment for their sharing. This distributed environment of network and software is also called electronic infrastructure or e-Infrastructure, while the technologies-services provided through this type of infrastructure enable new methods of research collaboration named electronic science or eScience. The combination of high-speed networks and broadband access, grid middleware services and advanced virtual collaboration technologies will lead to the creation of World Wide Grid. The creation of such infrastructure, which will provide integrated communication and information processing services is the main objective of the European Research Area.

HellasGrid is the biggest grid infrastructure at the area of Southern Eastern Europe and one of the most sustainable grid infrastructures at European level. The main scope of HellaGrid is the provision of High Performance Computing and High Throughput Computing services to Greek academic and research community. So, the resources of the grid infrastructure are used by Greek researches and researches involved at various European projects. The last years, an more and more increased number of researches coming from various scientific fields (high energy physics, computational chemistry, biomedicine, informatics, meteorology, seismology, etc.) uses the HellasGrid infrastructure in order to cover their needs for computational and storage resources. Access to HellasGrid infrastructure is free to Greek academic and research community, by following a simple registration procedure which is described here.

Figure 1 - HellasGrid infrastructure

The HellasGrid infrastructure is composed by six (6) clusters of computational and storage resources located at Athens (HG-01-GRNET, HG-02-IASA, HG-06-EKT), Thessaloniki (HG-03-AUTH), Patras (HG-04-CTI-CEID) and Heraklion (HG-05-FORTH). Also the HellasGrid Certification Authority has been created in order to issue digital certificates for users and servers, while two teams have been created for the support of Greek users: the User-Support Team and the Applications-Support Team.

The HellasGrid infrastructure is continuously adapted and upgraded according to the needs of its users, while the expanding of its resources is examined in order to cover future needs.