We introduce a new paradigm For Ihc design of parallel algorithms called eventual determinism. In an eventualfy-determinizing algorithm, all processes execute identical programs from identical starting states. A program has two parts (also called modes) —probabilistic and deterministic. A process begins execution in the probabilistic mode and eventually (with probability one) switches to a deterministic mode. The decision to switch is taken independently by each process. This means that it is possible for different processes to be executing in different modes at the same time. It is possible that a process may change back to the probabilistic mode but it is required that eventually, each process should switch and stay in the deterministic mode. Thus determinacy pervades the system.