I will give an overview of the newest and most interesting results concerning the physics of the top quark. I will present data from proton anti-proton scattering at a centre of mass energy of sqrt(s)=1.96 TeV which were recorded by the D0 experiment at the Tevatron accelerator. Besides the measurement of the top pair-production cross section, I will particularly discuss different methods to measure the mass of the top quark. I will also give examples for measurements of other properties of the top quark and of searches for new physics in the top sector. The talk will end with a brief outlook on the physics of the top quark at the Large Hadron Collider (LHC).