Density functional Theory (DFT), in principle, includes Van der Waals energies, but approximations rooted in the local density approximation (LDA), such as generalized gradient approximations (GGAs) do not. This talk will describe recent and ongoing work to use time-dependent density functional theory to calculate Van der Waals attractions between two systems of interacting atoms (molecules, clusters, solids, etc.) of arbitrary size, shape and composition.