The 9th International Federation for Automatic Control (IFAC) Workshop on Adaptation and Learning in Control and Signal Processing (ALCOSP 2007) and the 3rd IFAC Workshop on Periodic Control Systems (PSYCO 2007) were held in St. Petersburg on August 29-31, 2007. The Russian National Automatic Control Committee (RNACC), St. Petersburg RNACC Group, International Physics and Control Society (IPACS), St. Petersburg State University, and Institute for Problems of Mechanical Engineering, RAS, participated in organization of the workshop. F.L. Chernous'ko, member of Russian Acad. Sci. 'Optimal periodic motions of two-mass systems in resistive media' considered the problem of controllable motion of the two-mass mechanical systems under the action of various environmental friction forces. The final plenary meeting's much attention was attracted by the panel discussion. The workshop showed that the traditional subjects of the control theory are far form being exhausted.