Directed by Bryan Singer and written by Michael Dougherty, Dan Harris and David Hayter, from a story by Singer, Hayter and Zak Penn, it is the second installment in the X-Men film series, following X-Men (2000).
X2: X-Men United, also known as X2 and internationally as X-Men 2, is the sequel to X-Men and the second installment in the X-Men film series. The film was released worldwide on May 2, 2003.
Tightly scripted, solidly acted, and impressively ambitious, X2: X-Men United is bigger and better than its predecessor -- and a benchmark for comic sequels in general.