The AB Project (the AB can refer to "Anima-Body" or "After-Before") is a project mentioned in Zero Escape: Virtue's Last Reward and Zero Escape: Zero Time Dilemma.
It refers to the overall mission of Akane Kurashiki and Sigma Klim working with Crash Keys to have Sigma and Phi, two espers with the ability to SHIFT their consciousness back and forth in time, to 2028. In order to do this, Sigma and Phi need to hone their skills and prevent the Radical-6 apocalypse. The Nonary Game: Ambidex Edition is a part of the AB Project.
It began in 2029, after the C-END: 1 route in the Decision Game, and ended in 2074.