[en] The control of MHD instabilities and disruptions remains a problem for future tokamaks, and a number of experiments have been performed on the DITE and COMPASS-C tokamaks to develop control techniques. A variety of tools are available on these devices: LHCD, ECRH, and external resonant magnetic perturbations (RMP) inside and outside the vessels. The last two have been operated in fast feedback loops following rotating instabilities, as well as quasi-DC. Suppression of density limit disruptions with magnetic feedback has been demonstrated, as well as control of internal modes (m=1, n=1 and the sawtooth) using RF or magnetic feedback techniques. An extensive study of the effect of static RMPs on MHD activity has been performed which together with a new theoretical model sheds light on possible mechanisms for both mode stabilisation and stimulation of disruptions by external field perturbations. (author). 13 refs, 6 figs, 3 tabs