The present paper surveys the more recent techniques related to the swingby maneuver, where a spacecraft changes its energy and angular momentum by passing close to celestial bodies. It is focused on the literature related to extensions of this maneuver, with emphasis in the powered version, where an impulse is applied to the spacecraft near the closest approach. Several mathematical models are considered, including the patched-conics approximation for analytical studies, and the restricted three-body problem for the numerical simulations. The main goal is to show the models and the main conclusions available in the literature for those maneuvers. Some key results are shown to discuss important aspects of this maneuver, including the analysis of the energy variation of the spacecraft, the behavior of the trajectories and other applications.