This paper gives an overview on the specific contributions from the tokamak TEXTOR/TEXTOR-94 to plasma-wall-interaction research, putting emphasis on the erosion and deposition properties (in particular graphite), hydrogen recycling mechanisms (molecules and atoms) and the characteristics of impurity radiation. The improved knowledge about these processes helps one to understand the mechanisms underlying these techniques, which have been pioneered on TEXTOR-94 for actively influencing plasma-wall interaction: impurity control by thin coatings, power exhaust on large areas with radiation from seeded impurities and the extension of the density limit by the control of radiative instabilities (MARFE). Also, the novel concept of the Dynamic Ergodic Divertor is presented as an innovative tool for controlling plasma-wall interaction.