Swiss with a flair for languages

This Festschrift celebrates the career of one of the world's foremost computer-science pioneers. Niklaus Wirth, who hails from Switzerland, is known internationally for his contribution to programming language design, from the very successful Pascal of the 1970s through to successive languages such as Modula-2 and Oberon. What is less well known by those who have not met him is that Wirth is also an excellent educator and thereby an inspirer of research. His main maxim has always been to keep things simple, but he recognises that this is no easy task in the field of computer science, where the entropy of design and maintenance works inexorably against this noble aim.

This book includes contributions by many of Wirth's close colleagues, as well as offerings by well-known admirers such as Tony Hoare, who contributes an aptly succinct preface. It is split into six parts, the first providing a fairly straightforward historical overview of Wirth's major achievements.

He was born in 1934. He obtained his degree in electrical engineering from the Swiss Federal Institute of Technology (ETH) Zurich in 1959. He received an MSc from Laval University, Quebec, Canada, in 1960. He studied for his doctorate under the supervision of the pioneering computer designer Harry D. Huskey at the University of California, Berkeley. From 1963 to 1967 he taught as an assistant professor at the newly created computer science department at Stanford University in California and then at the University of Zurich. In 1968 he was appointed full professor of computer science at ETH Zurich.

In 1970 he devised the language Pascal; Modula-2 in about 1980; and in about 1988 a language with some object-oriented features named Oberon. He designed the Lilith and Ceres computers, and subsequently became involved with circuit design tools. He became head of the institute of computer systems at ETH in 1990 and retired on April 1 1999, prompting the production of this book.

Over the years, Wirth has received numerous honorary doctorates and awards including the 1984 Association for Computing Machinery Turing Award, computer science's nearest equivalent to a Nobel prize, and the 1987 Computer Pioneer Award from the Institute of Electrical and Electronics Engineers' Computer Society.

Pascal probably remains Wirth's best-known and most influential programming language. It was originally designed as a teaching tool to promote the structured programming style of another leading computing pioneer, Edsger W. Dijkstra, a contributor to this book. Pascal's simplicity was one of the secrets of its success. Wirth was able to develop a small and elegant Pascal compiler in the language itself, in marked contrast to some other more complicated programming languages that have been less widely adopted.

He developed his initial version of the Modula programming language as a research exercise, aimed at demonstrating that an operating system for a personal work station could be written entirely in a high-level language. The subsequent and much more widely used Modula-2 language was developed between about 1979 and 1981.

The Oberon project was launched in 1985 by Wirth with Jurg Gutknecht, one of the editors of this book. Oberon had many of the features of Modula-2, but some unneeded aspects were removed and other features were added. The project was originally targeted towards in-house hardware and this drove the language design, but versions of the Oberon language and system were made available for a number of commercial platforms.

Wirth is a true engineer by nature, with interests in both software and hardware, and this book reflects those interests. One of his most remarkable projects was the design of the Lilith personal workstation, based on the programming language Modula-2. It was influenced by the renowned Alto computer, designed at Xerox Palo Alto Research Center in the United States. Although both were technical triumphs, neither resulted in direct commercial success.

The second part of the book includes an autobiographical contribution by Wirth himself, in the form of his Turing Award acceptance lecture. A characteristically handwritten manuscript from fellow pioneer Dijkstra, while of technical interest, seems strangely out of place, apart from its brief initial dedication.

In the third part, the book moves on to perhaps more interesting and less well-known aspects. Personal accounts by Wirth's direct pupils focus on the technical aspects of their work with Wirth, and his constant striving for simplicity is emphasised.

Next come contributions by other colleagues and the industrial influence of Wirth's ideas and programming languages.

More personal and anecdotal accounts of the experience of working with Wirth include one by Kathleen Jensen who co-authored the original classic report on the Pascal programming language. Finally, there is a useful set of biographical notes on the contributing authors and editors and their contacts with Wirth.

Wirth will be remembered primarily as a prolific, expert and successful designer of imperative programming languages. He was important in the structured programming movement and his languages helped in the quest for more understandable programs. Although these aspects are covered, the book concentrates more on Wirth's work as a teacher at postgraduate level and beyond. It is obvious from it that while some of the contributors might have originally been daunted by Wirth's intellectual reputation, his low-key but inspiring leadership inevitably won the day. The book's very existence, not to mention its contents, is testament to this.

This book is a fitting tribute to Wirth. However, it is unlikely to have wide appeal except to those who already know of his impressive contribution to computer science. The non-computer scientist will probably not gain much apart from an appreciation of Wirth's laudable lifetime goal of always aiming for the simplest possible design. But I applaud the project, given Wirth's status within the computer-science community, as a worthwhile record for future computer-science historians.

Jonathan Bowen is professor of computing, South Bank University.