This special issue of Distributed Computing is based on four papers that originally appeared, in preliminary and abbreviated form, in the Proceedings of the 28th ACM Symposium on the Principles of Distributed Computing (PODC 2009), held in Calgary, Canada, on August 10–12. The papers were chosen by the Program Committee from the 27 full-length papers presented at the Symposium and are fine examples of the quality and diversity of the research presented at PODC. In the first paper, Randomized Mutual Exclusion with Sub-Logarithmic RMR-Complexity, Hendler and Woelfel shed new light on the fundamental mutual exclusion problem, showing that randomized mutual exclusion algorithms that use only reads and writes can overcome the logarithmic lower bound shownbyAttiya,Hendler, andWoelfel for deterministic algorithms, and achieve sub-logarithmic complexity when measured in terms of remote memory references (RMRs). The second paper, Load Balancing Without Regret in the Bulletin Board Model presents an excellent example of the growing interest of the PODC community in algorithmic game theory. Kleinberg, Piliouras, and Tardos study the performance of a simple, well-known, no-regret multiplicativeweights algorithm for a class of load balancing games in a model where players can query the current state of the system but cannot reliably predict the effect of their actions on it. Using non-standard analysis, they show that the makespan (i.e. the maximum load over all machines) achieved by this simple algorithm deviates in any step by at most O(log n) from the optimal makespan, a result that is exponentially