This book discusses the recent research work on designing efficient fault-tolerant synchronization mechanisms for concurrent processes using the relatively new persistent memory technology that combines the low latency benefits of DRAM with the persistence of magnetic disks. The authors include all of the major contributions published to date, and also convey some perspective regarding how the problem itself is evolving. The results are described at a high level to enable readers to gain a quick and thorough understanding of the RME problem and its nuances, as well as various solutions that have been designed to solve the problem under a variety of important conditions and how they compare to each other.