XtreemOS is aimed at investigating and proposing new services that could be added to current operating systems to build a Grid infrastructure in a simple way. While much has been done to build Grid middleware on top of existing operating systems, little has been done to extend the underlying operating systems for enabling and facilitating Grid computing.

The main outcome of the project is the XtreemOS software, a Grid operating system based on Linux. The main functionalities provided by XtreemOS are application execution management, data management and virtual organization management. Additionally, it offers a set of generic services to build highly available and scalable services and applications. XtreemOS will be released as a suite of Linux distributions customized for single PCs, clusters and mobile devices.

Transparency is one of the fundamental concepts that have driven the design of XtreemOS, in order to hide the complexity of Grid to both users and developers. On the one hand, users will have the feeling that they work on a traditional Linux machine, and in the other job execution and data access in the Grid will be transparent for applications and developers.

XtreemOS is fully committed with standardisation, as we plan to serve three kinds of applications: existing Linux applications, using POSIX-standardized interfaces; existing Grid applications, using OGF-standardized interfaces; and new applications, which may use advanced functionalities only provided by XtreemOS. To this end, the project has selected the emerging OGF standard Simple API for Grid Applications (SAGA) as building block of the XtreemOS API,as it combines OGF-standardised APIs with POSIX-like interfaces.

Several partners of the XtreemOS Consortium are strongly involved in OGF and OGF-Europe, and we hope to contribute to OGF's efforts providing a worthy feedback and visibility.