Since its first release 20 years ago, "the dinosaur book" - Operating System Concepts by Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne - has become a valuable reference for designers and implementers operating system. There is also information about how the latest crop of operating systems, including Microsoft Windows 2000, Linux, FreeBSD, and compact operating systems for handheld devices. This book is related to the design of operating systems, which said it mentions the problems that arise in the creation of efficient systems and explores alternative ways to deal with them, detailing the advantages and disadvantages of each. They highlight the relative advantages of each, and explain how real-life operating systems solve some problems. Problem of scheduling the CPU, memory allocation, paging, processes and threads, storage management, distribution process and storage mechanisms, and security of all discussed thoroughly and with many authoritative references.