Many physical, biological or sociological systems, though coming from individually simple items, exhibit high complexity when observed globally. These have been studied as complex systems. Among considered models, cellular automata, tilings by Wang tiles (or by finite subsets of a group), Turing machines, various kinds of picture-walking automata or of substitutions, have all been studied through the light of topological dynamics, ergodic theory, combinatorics, and more recently formal language theory, computability, complexity. This conference will also be the opportunity to celebrate Jarkko Kari’s 60th birthday.