Discrete Mechanics, Geometric Integration and Lie–Butcher SeriesThis volume resulted from presentations given at the international Brainstorming Workshop on New Developments in Discrete Mechanics, Geometric Integration and LieButcher Series, that took place at the Instituto de Ciencias Matemticas (ICMAT) in Madrid, Spain. It combines overview and research articles on recent and ongoing developments, as well as new research directions. Why geometric numerical integration? In their article of the same title Arieh