Book excerpt: Geometric programming is used for design and cost optimization and the development of generalized design relationships and cost rations for specific problems. The early pioneers of the process, Zener, Duffin, Peterson, Beightler, and Wilde, played important roles in the development of geometric programming. The theory of geometric programming is presented and 10 examples are presented and solved in detail. The examples illustrate some of the difficulties encountered in typical problems and techniques for overcoming these difficulties. The primal-dual relationships are used to illustrate how to determine the primal variables from the dual solution. These primal-dual relationships can be used to determine additional dual equations when the degrees of difficulty are positive. The goal of this work is to have readers develop more case studies to further the application of this exciting mathematical tool. Table of Contents: Introduction / Brief History of Geometric Programming / Theoretical Considerations / Trash Can Case Study / Open Cargo Shipping Box Case Study / Metal Casting Cylindrical Riser Case Study / Process Furnace Design Case Study / Gas Transmission Pipeline Case Study / Journal Bearing Design Case Study / Metal Casting Hemispherical Top Cylindrical Side Riser / Liquefied Petroleum Gas(LPG) Cylinders Case Study / Material Removal/Metal Cutting Economics Case Study / Summary and Future Directions