Professor Nivat obtained his Thèse d'Etat: Transductions des langages de Chomsky, under the supervision of Marcel-Paul Schützenberger, at L'Ecole Normal Superieur de Paris in 1967. Since then, he has made fundamental contributions to different fields of theoretical computer science. First in the area of Formal Languages: he introduced and studied the rational cone, languages defined by congruences, the generators of contextfree languages, and the topological approach to the study of formal languages. Algebraic semantics is prof. Nivat's second main achievement: his insight was that the semantics of a recursive program scheme is given by an infinite algebraic object which is the solution of a set of equations on sets of terms associated to the program scheme. Prof. Nivat's third main achievement is a consequence of his collaboration with Thomson CSF in the late nineteen seventies: he introduced the synchronized product of finite automata to describe and model concurrent systems. This early work has given rise to model-checking, and can therefore be seen as the foundation for the actual commercial verification tools. Much later, he changed his research direction once more, turning his attention to discrete geometrical objects and becoming a prominent researcher in the study of tilings and discrete tomography. Nowadays, prof. Nivat is one of the most active promoters in this field. Recently, prof. Nivat has become also interested in the problem of the phase transition for SAT, as a characterisation of difficult vs. easy problems.
Professor Nivat had a lasting influence on the development of French and European computer science. In 1972 prof. Nivat was on of the founders of the European Association for Theoretical Computer Science, and he was its first president (1972-77). During 25 years prof. Nivat has been the editor-in-chief of the journal Theoretical Computer Science. Prof. Nivat has participated in the creation of multiple initiatives related to theoretical computer science: ICALP, TAPSOFT, ETAPS, etc. From 1981 to 1985 prof. Nivat was president of the Conseil Scientifique du programme Mobilisateur de la Filière Electronique, under president Mitterand. From this position, he promoted in France, the development of computer science as a separate discipline.
Maurice Nivat made most of his career as Professor of Computer Science at the Universite de Paris 7, where he created the famous LITP across two universities: Paris 7 and Paris 6. As the director or advisor of numerous young researchers who all became his friends, he had a lasting influence of the French and Catalan schools of theoretical computer science, and had many contacts with computer science and all over the world.
Professor Nivat also has made excellent contributions to the introduction of the discipline of theoretical computer science in Latin America, Africa and Asia.