The article by Fulde, Thalmeier and Zwicknagl traces many of the recent developments in the field of strongly correlated many electron systems. It is very useful both as a reference and a pedagogical exposition since it places these developments into a historical context beginning with early developments in the electron theory of solids. The second article in this volume, by Br?©chet and Hutchinson, concerns pattern formation in metals and alloys. Spontaneous pattern formation is the development of a regularity, either in the spatial distribution of the material in a system or in its development in time, of a lower symmetry than that of its cause. These phenomena have been of considerable interest to the non-linear physics community, in particular in fluid dynamics and in chemical reactions.