Writers and directors such as Robert Wilson, María Irene Fornes, Richard Foreman, Caryl Churchill, Elizabeth LeCompte, Judith Malina, Julian Beck, Peter Brook, Ed Bullins, and Joseph Chaikin challenged our notions of space and duration, meaning and eventfulness, theatricality and chance. They revolutionized our sense of what a play might be. That was their revolution. What is our avant-garde?