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This month, we are pleased to provide to our readers a column that addresses an important aspect of grid computing: data access. Grid computing is important and relevant because it provides middleware that supports secure and managed sharing of networked computational resources. This is valuable because many activities involve collaborations that stand to benefit from more efficient and systematic access to computational and data resources across management domains. The GGF is important because the development of grids depends on shared abstractions and consistent interfaces; the GGF is the principal standards body for grid computing. For the most part, the GGF is developing web service standards for resource management and use that can be used relatively independently or as part of a wider service-based architecture. The authors of the note belong to two overlapping groups: the chairs of the GGF Data Access and Integration Services Working Group, and the members of the Design Team that was responsible for writing the specifications, and for evolving them in the light of input from other members of the working group and the wider community.

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• Virtualized-allowing a collection of distributed information resources to be shared and managed as if they were a single information store, although they may in fact remain fully distributed. • Autonomic-ensuring that the interconnected information systems can be managed effectively and efficiently through self-management just like the human autonomic nervous system. • Open-utilizing open interfaces and agreed-upon standards to enable highly interoperable systems and processes.

Although the Extensible Markup Language (XML) has gained in popularity and has resulted in the creation of powerful software for authoring, transforming, and querying XML-based business data, much information remains in non-XML form. In this paper we introduce an approach to virtualize data resources and thus enable applications to access both XML and non-XML sources. We describe the architectural components that enable virtual XML-a toolbox that includes a cursor model, an XML-view mechanism such as the view created with the Data Format Description Language (DFDL), and XML processing languages. We illustrate the applicability of virtual XML through a number of use cases in various environments. We discuss the products that we expect from vendors and the open-source community and the way enterprises can plan to take advantage of virtual XML developments. Finally, we outline future research directions that include a vision of virtual XML that covers large-scale structures such as entire file systems, databases, or even the World Wide Web. 1 which offers a relational interface to heterogeneous data. This paper discusses the idea of information virtualization by using the Extensible Markup Language (XML) data model as the framework. Despite predictions to the contrary, XML has become a very successful notation for information exchange between disparate systems. The technologies, tools, and knowledge accumulated over XML's long ancestry starting with SGML (Standard Generalized Markup Language) 2 have contributed to its success. XML's support of different platforms and