‘Geometry and Concurrency’ is not (yet) a well-established domain of research, but consists
rather of a collection of seemingly related techniques, algorithms and formalizations,
coming from different application areas, and accumulated over a long period of time.
There is currently a certain amount of effort being made to unify these, following
the workshop ‘New Connections between Computer Science and Mathematics’ held at
the Newton Institute in Cambridge, England in November 1995 (and sponsored by
HP/BRIMS). More recently, the first workshop on the same subject was held in Aalborg,
Denmark (see http://www.math.auc.dk/˜raussen/admin/workshop/workshop.html)
where the articles of this issue, among others, were first sketched.
As a starter, and to put in context the papers by Lisbeth Fajstrup, Philippe Gaucher,
Maurice Herlihy, Vaughan Pratt, Sergio Rajsbaum and Martin Raussen that appear later
in this issue, I have written a brief historical note, or survey, which follows and naturally
completes this foreword.
Last and not least, I must express my gratitude to Giuseppe Longo, who gave me the
opportunity to act as a guest editor for this special issue, and who very kindly helped
me through the many different steps that editing necessitates. My very warm thanks also
go to the authors who did a very nice job, in a relatively short time. Finally, I wish to
thank the referees of this issue, who found ‘bugs’ that I would not have found, and who
suggested very useful improvements to the authors. The referees were Nir Shavit, Stefan
Sokolowski, Christophe Tabacznyj, Jean Goubault-Larrecq, Arnaud Venet, Ian Mackie
(who helped me with the survey article), Ronnie Brown and Tim Porter, as well as some of
the authors who cross-checked other authors' articles, Philippe Gaucher, Martin Raussen
and Lisbeth Fajstrup.