Tomorrow, the Science Faculty of the University of Pisa (my Italian alma mater) will host the colloquium

Concurrency, Graphs and Models in honour of

Ugo Montanari on the occasion of his forthcoming 65th birthday. The invited speakers for the event are:

Apart from being outstanding scientists, the speakers cover some of the many areas of theoretical computer science to which Ugo has contributed over the years. Apart from being a very productive scientist, the

DBLP lists 272 of his publications as of today, Ugo has given important contributions to the theory of constraint programming, to graph grammars, to the theory of concurrency, to the theory of abstract data types (final algebra semantics for ADTs), to categorical models of concurrent computation (see his paper

Petri Nets are Monoids co-authored with Meseguer, and his work on the

tile model) and to algorithmics (see for instance his efficient

unification algorithm developed with

Alberto Martelli), amongst others.

Apart from the influence that Ugo has had on the Italian TCS community via his research, one cannot help but marvel at the number of former students of his who are now in leading positions in Italian computer science. Ugo's influence, and that of his students, is one of the reasons why when I go to a concurrency theory conference, Italians seem to be everywhere.

On a personal note, some of the best academically-related memories I have of my student days in Pisa are related to a year-long course I took with Ugo during my third year. As I remember it, the course was a veritable tour-de-force covering topics in computability, automata and formal languages, abstract data types, some logic, denotational semantics and its application to programming-language semantics. The best part of it was, however, the week-long take-home group exam that we took. It was the only such exam I ever took in Pisa, and my friends and I learned a lot while working on it. By the time the assignment was over, we had composed a song about Ugo that showed the huge respect we had for him. One of the verses read: "this chain is too long, nobody can find an upper bound for it, but Montanari" :-)

Ugo was also the examiner for my MSc thesis at the University of Pisa, which I finished in 1986 under the supervision of Rocco De Nicola, who had been an MSc student of Ugo's himself. So, in some sense, I am an academic grandchild of Ugo's. Finally let me remark that Ugo was also one of the prime movers behind the

BRA project CEDYSIS, under which I was employed during my doctoral studies at the University of Sussex.

Many happy returns, Ugo. Enjoy the day!

P.S.: Any reader who would like to author a guest post on Ugo's work or on his influence on the TCS research community is most welcome to send it to me. I'll be happy to post the contributions I receive.