We demonstrate the benefits of software shared memory protocols that adapt at run time to the memory access patterns observed in the applications. This adaptation is automatic-no user annotations are required-and does not rely on compiler support or special hardware. We investigate adaptation between singleand multiple-writer protocols, dynamic aggregation of pages into a larger transfer unit, and adaptation between invalidate and update. Our results indicate that adaptation between single- and multiple-writer and dynamic page aggregation are clearly beneficial. The results for the adaptation between invalidate and update are less compelling, showing at best gains similar to the dynamic aggregation adaptation and at worst serious performance deterioration.