and managing state components, but differs according to both its precise syntax and the use made (or not) of conventional domain-independent encodings of operations.

Thus, when defining state management operations, the WS-RF and WS-Transfer approaches both use EPRs to refer to state components and to adopt conventions defined in the WS-RF and related specifications and in the WS-Transfer and related specifications, respectively. In contrast, the no-conventions and REST approaches adopt domain-specific encodings of operations, on top of SOAP and HTTP, respectively.

Analysis of the debates that have occurred around these different approaches emphasizes the difficulties inherent in separating technical, political, and stylistic concerns. Some differences of opinion relate to well-defined technical issues and reflect either different philosophies concerning system design or different target applications. Others relate to differing target time scales. For example, no-conventions proponents initially argued against the use of WS-Addressing because of lack of support for that specification in certain tools, while WS-RF and WS-Transfer proponents argued in favor, believing that WS-Addressing would eventually become universal. Support for WS-Addressing has since become quasi-universal, and now few find its use objectionable. Q

 

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ACKNOWLEDGMENTS We are grateful to Karl Czajkowski, Jim Gray, and Sam Meder for comments on an earlier version of this document. Needless to say, the characterizations of the different arguments are our own. The work of the first author was supported in part by the Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, U.S. Department of Energy, under Contract W-31-109-Eng- 38. The work at Newcastle was supported by the UK eScience Programme, with funding from the EPSRC, DTI, and JISC.

 

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IAN FOSTER ( foster@anl.gov) is the director of the Computation Institute at Argonne National Laboratory, where he is an Argonne Distinguished Fellow, and the University of Chicago, where he is the Arthur Holly Compton Distinguished Service Professor of computer science.

SAVAS PARASTATIDIS ( Savas.Parastatidis@newcastle. ac.uk) is an architect for Microsoft Research. He investigates the use of technology in e-research and is particularly interested in cloud computing, knowledge representation and management, and social networking. PAUL WATSON (Paul. Watson@newcastle.ac.uk) is a professor of computer science at Newcastle University, and director of the North East Regional e-Science Centre in the U.K. MARK McKEOWN was a grid architect at the University of Manchester, U.K., at the time of this work. © 2009 ACM 1542-7730 /09/0200 $5.00

This article appears in print in the September 2008 issue of Communications of the ACM.