from Wikipedia:

Wicked is a Tony award-winning American musical produced by Universal Pictures with music and lyrics by Stephen Schwartz, and a book by Winnie Holzman. The story is loosely based on the best selling novel Wicked: The Life and Times of the Wicked Witch of the West by Gregory Maguire, a re-imagining of L. Frank Baum's classic story, The Wonderful Wizard of Oz from the point of view of the witches of Oz. The musical follows the stories of Glinda and Elphaba, two young witches who eventually become the Good Witch of the North and the Wicked Witch of the West respectively, and is set mostly prior to Dorothy's arrival from Kansas. The plot also makes several references to the classic 1939 film.

The musical opened first on Broadway on October 30, 2003, directed by Joe Mantello and starring Kristin Chenoweth, Idina Menzel and Joel Grey, with musical staging by Wayne Cilento.