Computational biology, materials science or nanoscience often require using quantum chemical methods to reach quantitative information on large and complex systems, in particular energy changes, accurate microscopic structures, ligand binding, spectroscopic parameters. Models of such systems may contain several hundreds of atoms and thousands of basis functions. This task demands a program that can perform calculations with a reasonable accuracy in a reasonable amount of time (typically calculation times of a few days). During the past decades, Density Functional Theory (DFT) has become the most widely used method in theoretical chemistry to investigate properties of systems containing from a few tens to hundreds of atoms. deMon is a system of programs developed around DFT calculations of atoms, molecules, clusters and solids. In order to treat large systems with all-electron first-principles methods, approximations to the basic theory, here Kohn–Sham DFT, are inevitable. The efficiency of a program depends on a mixture of the theoretical model used and the translation of the model into a computer code. This proposal aims at gathering most of the community of the deMon developers and organizing contacts and practical exchanges with researchers from other theoretical communities.  The workshop will be held in Toulouse in spring 2013, organized by the CFCAM-GSO node. More than a general conference on the DFT, the workshop goal is to focus on the recent and future developments and implementations to provide an efficient suite of programs pushing forward the limitations in terms of applications. The status of the deMon code will be examined and the future perspectives outlined. Oral Communications, posters, working groups and round tables will be organized.