Program storage inordinate briefly that XP also. ... a methodology of software development in which the goal is to increase software quality and responsiveness to the needs of the changing user. As the strains of the development of Agile software (agile software developmnet) of the release (release), alternating in short cycle development, with the aim of improving production capabilities and the introduction of points of control (Check Point) to comply with the needs of the new user, to defend.