Aperiodic 2000 continued a series of conferences on Modulated Structures, Polytypes and Quasicrystals, starting as MOSPOQ and continued as Aperiodic. At the conference in Nijmegen 139 participants convened from 25 different countries. Thirty-four of them came from outside Europe. The number of participants was approximately equal to that at previous conferences, showing that the field of aperiodic crystals remains very interesting. An attractive facet of the Aperiodic conferences is their broadness. Among the participants are mathematicians, theoretical and experimental physicists, chemists, crystallographers and material scientists. Such a meeting helps to make scientists from different communities to become familiar with problems and concepts in related fields.

Although the relative importance of incommensurately modulated crystals and of polytypes has diminished as compared to quasicrystals, they were still well represented. The role of quasicrystals has grown and accounted for approximately 40% of the talks. There is a further development in incommensurate composite structures. In this subfield we could welcome some new participants from chemistry.

The program included besides oral contributions and posters also two tutorials for the benefit of participants less familiar with certain subfields. One was given by Denis Gratias, on crystallography of quasicrystals, another by Michel Van Hove on surfaces of aperiodic crystals.

During the conference Denis Gratias made the proposal to dedicate the proceedings to the memory of P.M. de Wolff who died since the last Aperiodic conference.

The proceedings of Aperiodic have been published as volume 250 of the journal Ferroelectrics (publication date February 2001). Ferroelectrics is published by Gordon and Breach Science Publishers.