Universal Acessibility to the Grid via Metagrid Infrastructure August 24, 2006 Soha Maad (soha.maad@cs.tcd.ie), Brian Coghlan (coghlan@cs.tcd.ie), Ea- monn Kenny (eamonn.kenny@cs.tcd.ie), Gabriel Pierantoni (pierantg@cs.tcd.ie), Oliver Lyttleton (oliver.lyttleton@cs.tcd.ie), David O’Callaghan (david.ocallaghan@cs.tcd.ie) Department of Computer Science, Trinity College Dublin 1 Extended Abstract This paper discusses the concept of universal accessibility [1, 2] to the grid within the context of selected application domains involving social interaction such as e-hospital, collaborative engineering, enterprise, e-government, and the media. Based on this discussion the paper proposes a metagrid infrastructure [3] as an approach to provide universal accessibility to the grid. Universal accessibility is rooted in the concept of Design for All in Human Computer Interaction[1, 2]. It aims at efficiently and effectively addressing the numerous and diverse accessibility problems in human interaction with software applications and telematic services. So far, the key concept of universal accessi- bility has been supported by various development methodologies and platforms [4, 5]. Various application domains benefited from research and development in this area, including among others interactive television and media [6, 7]. Port- ing the concept of universal accessibility to the grid is faced by major obstacles attributed to the following: (a) the lack of an underlying functionality similar to that of a desktop operating system allowing the plug and play of resources and the direct user interaction with these resources; (b) the dilemma between hiding the grid versus making it more transparent; and (c) the software engineering practice adopted in grid middleware development, where the bottom up ap- proach that is predominant [8] conflicts with the ethos of universal accessibility that considers accessibility at design time. These obstacles and their impacts on universal accessibility to the grid are discussed with reference to four application domains including collaborative ap- plications such as e-hospital, collaborative engineering, enterprise applications, the media, and e-government. In collaborative applications the key obstacle for universal accessibility to the grid is provision of interactivity while respecting various Service Level Agreements (SLAs). Several efforts are underway to re- solve this issue [9, 21], but no versatile solutions have emerged so far. In the 1