Language prototyping provides a means to generate language implementations automatically from high-level language definitions. This volume presents an algebraic specification approach to language prototyping, and is centered around the ASF+SDF formalism and Meta-Environment. The volume is an integrated collection of articles covering a number of case studies, and includes several chapters proposing new techniques for deriving advanced language implementations. The accompanying software is freely available.

This volume presents the proceedings of the 14th International Conference on the Foundations of Software Technology and Theoretical Computer Science, FST&TCS-14, held in Madras, India in December 1994. Besides the five invited papers by well-known researchers, it includes 31 full refereed research papers selected out of a total of 140 submissions. The papers contribute to the whole area of theoretical computer science with an emphasis on algorithms and complexity. Other topics covered are program semantics, program verification, formal logic, computational geometry, concurrency, unification, and discrete mathematics.

This volume contains the proceedings of the 21st international conference on the Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2001), organized under the auspices of the Indian Association for Research in Computing Science (IARCS). This year’s conference attracted 73 submissions from 20 countries. Each s- mission was reviewed by at least three independent referees. In a departure from previous conferences, the ?nal selection of the papers making up the program was done through an electronic discussion spanning two weeks, without a physical meeting of the Program Committee (PC). Since the PC of FSTTCS is distributed across the globe, it is very di?cult to ?x a meeting whose time and venue is convenient for a substantial fraction of the PC. Given this, it was felt that an electronic discussion would enable all members to participate on a more equal footing in the ?nal selection. All reviews, scores, and comments were posted on a secure website, with a mechanism for making updates and automatically sending noti?cations by email to relevant members of the PC. All PC members participated actively in the discussion. The general feedback on the arrangement was very positive, so we hope to continue this in future years. We had ?ve invited speakers this year: Eric Allender, Sanjeev Arora, David Harel, Colin Stirling, and Uri Zwick. We thank them for having readily accepted our invitation to talk at the conference and for providing abstracts (and even full papers) for the proceedings.

The goal of the AMAST conferences is to foster algebraic methodology as a foundation for software technology, and to show that this can lead to practical mathematical alternatives to the ad-hoc approaches commonly used in software engineering and development. The first two AMAST conferences, held in May 1989 and May 1991 at the University of Iowa, were well received and encouraged the regular organization of further AMAST conferences on a biennial schedule. The third Conference on Algebraic Methodology and Software Technology was held in the campus of the University of Twente, The Netherlands, during the first week of Summer 1993. Nearly a hundred people from all continents attended the conference. The largest interest received by the AMAST conference among the professionals extended to include the administration organizations as well. AMAST'93 was opened by the Rector of the University of Twente, followed by the Local Chairman. Their opening addresses open this proceedings, too. The proceedings contains 8 invited papers and 32 selected communica tions. The selection was very strict, for 121 submissions were received.

An Approach to Complexity from a Human-Centered Artificial Intelligence Perspective to The Virtual Workplace