Few works are as timely and critical to the advancement of high performance computing than is this new up-to-date treatise on leading-edge directions of operating systems. It is a first-hand product of many of the leaders in this rapidly evolving field and possibly the most comprehensive. This new and important book masterfully presents the major alternative concepts driving the future of operating system design for high performance computing. In particular, it describes the major advances of monolithic operating systems such as Linux and Unix that dominate the TOP500 list. It also presents the state of the art in lightweight kernels that exhibit high efficiency and scalability at the loss of generality. Finally, this work looks forward to possibly the most promising strategy of a hybrid structure combining full service functionality with lightweight kernel operation. With this, it is likely that this new work will find its way on the shelves of almost everyone who is in any way engaged in the multi-discipline of high performance computing. (From the foreword by Thomas Sterling)