"In total, the two books Solaris Performance and Tools & Solaris Internals reviewed here present a new level of knowledge about the internals of Solaris, what they do, how they behave, and how to analyze that behavior. The books are a must for developers, system programmers, and systems administrators who work with Solaris 8, 9, or 10. They are especially useful for users of Solaris 10 and OpenSolaris because of their exploration of the new tools in those releases. These books receive my highest recommendation. "—Peter Baer Galvin, Contributing Editor, Sys Admin Magazine