Dynamic atomic force microscopy, in essence, consists of a vibrating microcantilever with a nanoscale tip that interacts with a sample surface via short- and long-range intermolecular forces. Microcantilevers possess several distinct eigenmodes and the tip-sample interaction forces are highly nonlinear. As a consequence, cantilevers vibrate in interesting, often unanticipated ways; some are detrimental to imaging stability, while others can be exploited to enhance performance. Understanding these phenomena can offer deep insight into the physics of dynamic atomic force microscopy and provide exciting possibilities for achieving improved material contrast with gentle imaging forces in the next generation of instruments. Here we summarize recent research developments on cantilever dynamics in the atomic force microscope.