Advances in biophysics and biochemistry have pushed back the limits of the structural characterization of biomolecular assemblies. Mixing even a limited amount of experimental and/or bioinformatics data with modeling methods such as macromolecular docking represents a valuable strategy to predict the three-dimensional structures of complexes. In this chapter, we discuss the HADDOCK data-driven approach to the modeling of complexes. The program supports a wide range of NMR and other experimental data as well as bioinformatics predictions. It is also available as a user-friendly web server, facilitating the modeling of biomolecular complexes for a wide community.