Novel experimental techniques allow detailed investigations of complicated molecular phenomena at hitherto unprecedented accuracy, such as rearrangement of individual atoms and bonds during chemical reactions. Typically, ultrashort and intense laser pulses are used in order to probe and manipulate the molecules. The goal of the AttoDyn project is to investigate and develop theoretical and computational tools to plan, understand, and predict such experiments, probing the quantum dynamics of molecular systems at the timescale of its lightest constituents, the electrons. These move on the attosecond timescale, a billionth of a billionth second. Furthermore, the motion of molecular systems under the influence of intense ultrashort laser pulses used in modern experiments often violate the almost universally accepted Born—Oppenheimer approximation. By removing this approximation, all electrons and atomic nuclei must be explicitly accounted for by quantum mechanics in simulations, which is a great theoretical challenge. The AttoDyn project uses an interdisciplinary team of theoretical chemists, physicists, and mathematicians to approach the complicated task of developing computational tools.