Physics of an Electron Ion Collider

Deep inelastic scattering (DIS) has been a very effective technique in physics in the discovery and the systematic study of the internal structure of matter. Three proposals for future experimentation employing this technique for the next decade, currently under consideration, are presented in this paper. We give a brief overview of each, and while their physics reach is wider, we present some highlights of physics motivation limited to the field of Quantum Chromodynamics.