Our Society's need to exchange greater and greater amounts of information has created an unprecedented demand for highly linear power amplifiers. High linearity is required for the spectrally efficient transmission of information. This presentation will discuss techniques for the cancellation of distortion that are also known as linearization. Different methods of linearization including digital approaches will be introduced and compared. The linearization of solid-state power amplifiers, traveling wave tubes amplifiers and klystron power amplifiers will be considered. Criteria for the evaluation of linearity will be reviewed and special attention given to problems unique to SSPAs.