The proposed next generation accelerator and synchrotron light facilities will require active feedback systems to control multi‐bunch instabilities. These feedback systems must operate in machines with thousands of circulating bunches and with short (2–4 ns) interbunch intervals. The functional requirements for transferse (betatron) and longitudinal (synchrotron) feedback systems are presented. Several possible implementation options are discussed and system requirements developed. Results are presented from a digital signal processing based synchrotron oscillation damper operating at the SSRL/SLAC SPEAR storage ring.