The DP code belongs to a large project, aimed at the creation of an European Theoretical Spectroscopy Facility, very much like an experimental synchrotron facility. Into this facility, we will aim at providing the theory, the know-how and the codes to describe condensed matter spectroscopy and excited state properties.
The EXC code has Optical and Dielectric Spectroscopy functionalities, but it is using a different theory, Many-Body Perturbation Theory (MBPT) and the Bethe-Salpeter Equation (BSE) to calculate them.
The Octopus code is a real space-time TDDFT code, well suited to 0-dimensional systems (atoms, molecules, clusters).
The Self code has TDDFT functionalities very much like the DP code.