Euro-ParConferenceSeries The European Conference on Parallel Computing (Euro-Par) is an international conference series dedicated to the promotion and advancement of all aspects of parallel and distributed computing. The major themes fall into the categories of hardware, software, algorithms, and applications. This year, new and interesting topicswereintroduced,likePeer-to-PeerComputing,DistributedMultimedia- stems, and Mobile and Ubiquitous Computing. For the ?rst time, we organized a Demo Session showing many challenging applications. The general objective of Euro-Par is to provide a forum promoting the de- lopment of parallel and distributed computing both as an industrial technique and an academic discipline, extending the frontiers of both the state of the art and the state of the practice. The industrial importance of parallel and dist- buted computing is supported this year by a special Industrial Session as well as a vendors’ exhibition. This is particularly important as currently parallel and distributed computing is evolving into a globally important technology; the b- zword Grid Computing clearly expresses this move. In addition, the trend to a - bile world is clearly visible in this year’s Euro-Par. ThemainaudienceforandparticipantsatEuro-Parareresearchersinaca- mic departments, industrial organizations, and government laboratories. Euro- Par aims to become the primary choice of such professionals for the presentation of new results in their speci?c areas. Euro-Par has its own Internet domain with a permanent Web site where the history of the conference series is described: http://www.euro-par.org. The Euro-Par conference series is sponsored by the Association for Computer Machinery (ACM) and the International Federation for Information Processing (IFIP).

by Joseph Weizenbaum Since the dawn of the age of computers, people have cursed the difficulty of programming. Over and over again we encounter the suggestion that we should be able to communicate to a computer in natural language what we want it to do. Unfortunately, such advice rests upon a misconception of both the computer and its task. The computer might not be stupid, but it is stubborn. That is, the computer does what all the details of its pro­ gram command it to do, i. e. , what the programmer "tells" it to do. And this can be quite different from what the programmer intended. The misun­ derstanding with respect to tasks posed to the computer arises from the failure to recognize that such tasks can scarcely be expressed in natural language, if indeed at all. For example, can we practice music, chemistry or mathematics without their respective special symbolic languages? Yet books about computers and programming languages can be written more or less reasonably, even if they are not quite poetic or lyrical. This book can serve as an example of this art and as a model for anyone at­ tempting to teach inherently difficult subject matters to others. Klagenfurt, April 1995 Preface Striving to make learning to program easier, this book addresses primarily students beginning a computer science major. For our program examples, we employ a new, elegant programming language, Modula-3.

Euro-ParConferenceSeries The European Conference on Parallel Computing (Euro-Par) is an international conference series dedicated to the promotion and advancement of all aspects of parallel and distributed computing. The major themes fall into the categories of hardware, software, algorithms, and applications. This year, new and interesting topicswereintroduced,likePeer-to-PeerComputing,DistributedMultimedia- stems, and Mobile and Ubiquitous Computing. For the ?rst time, we organized a Demo Session showing many challenging applications. The general objective of Euro-Par is to provide a forum promoting the de- lopment of parallel and distributed computing both as an industrial technique and an academic discipline, extending the frontiers of both the state of the art and the state of the practice. The industrial importance of parallel and dist- buted computing is supported this year by a special Industrial Session as well as a vendors’ exhibition. This is particularly important as currently parallel and distributed computing is evolving into a globally important technology; the b- zword Grid Computing clearly expresses this move. In addition, the trend to a - bile world is clearly visible in this year’s Euro-Par. ThemainaudienceforandparticipantsatEuro-Parareresearchersinaca- mic departments, industrial organizations, and government laboratories. Euro- Par aims to become the primary choice of such professionals for the presentation of new results in their speci?c areas. Euro-Par has its own Internet domain with a permanent Web site where the history of the conference series is described: http://www.euro-par.org. The Euro-Par conference series is sponsored by the Association for Computer Machinery (ACM) and the International Federation for Information Processing (IFIP).

by Joseph Weizenbaum Since the dawn of the age of computers, people have cursed the difficulty of programming. Over and over again we encounter the suggestion that we should be able to communicate to a computer in natural language what we want it to do. Unfortunately, such advice rests upon a misconception of both the computer and its task. The computer might not be stupid, but it is stubborn. That is, the computer does what all the details of its pro­ gram command it to do, i. e. , what the programmer "tells" it to do. And this can be quite different from what the programmer intended. The misun­ derstanding with respect to tasks posed to the computer arises from the failure to recognize that such tasks can scarcely be expressed in natural language, if indeed at all. For example, can we practice music, chemistry or mathematics without their respective special symbolic languages? Yet books about computers and programming languages can be written more or less reasonably, even if they are not quite poetic or lyrical. This book can serve as an example of this art and as a model for anyone at­ tempting to teach inherently difficult subject matters to others. Klagenfurt, April 1995 Preface Striving to make learning to program easier, this book addresses primarily students beginning a computer science major. For our program examples, we employ a new, elegant programming language, Modula-3.