The TEXTOR research programme focuses on the systematic analysis of plasma wall interaction, the development of a suitable wall system and the production of quasi-stationary long-pulse high-temperature plasmas with tolerable impurity concentrations, with well-defined boundary layer and with relevant particle and power fluxes through the boundary. The authors describe the method of wall carbonization developed in Julich and some characteristic features of the TEXTOR plasma obtained with this method for both metal limiters and graphite limiters. Moreover, the effect of ICRH heating (2 MW, 1 sec) on plasma parameters and on the boundary layer is discussed, together with the application of the single head pump limiter ALT-I and of the localized set of magnetic perturbation coils for boundary 'ergodization'.