This book presents novel symbolic control and data flow techniques as well as symbolic techniques and algorithms for program analysis and program optimization. Program contexts, defining a new symbolic description of program semantics for control and data flow analysis, are at the center of the techniques and methods introduced. The authors develop solutions for a number of problems encountered in program analysis by using program contexts. The solutions proposed are efficient, versatile, unified, and more general than most existing methods. The authors' symbolic analysis framework is implemented as a prototype as part of the Vienna High Performance Compiler.