Book excerpt: Geometric programming is used for design and cost optimization, the development of generalized design relationships, cost ratios for specific problems, and profit maximization. The early pioneers of the process - Zener, Duffin, Peterson, Beightler, Wilde, and Phillips -- played important roles in the development of geometric programming. There are three major areas: 1) Introduction, History, and Theoretical Fundamentals, 2) Applications with Zero Degrees of Difficulty, and 3) Applications with Positive Degrees of Difficulty. The primal-dual relationships are used to illustrate how to determine the primal variables from the dual solution and how to determine additional dual equations when the degrees of difficulty are positive. A new technique for determining additional equations for the dual, Dimensional Analysis, is demonstrated. The various solution techniques of the constrained derivative approach, the condensation of terms, and dimensional analysis are illustrated with example problems. The goal of this work is to have readers develop more case studies to further the application of this exciting tool. Table of Contents: Introduction / Brief History of Geometric Programming / Theoretical Considerations / The Optimal Box Design Case Study / Trash Can Case Study / The Open Cargo Shipping Box Case Study / Metal Casting Cylindrical Riser Case Study / Inventory Model Case Study / Process Furnace Design Case Study / Gas Transmission Pipeline Case Study / Profit Maximization Case Study / Material Removal/Metal Cutting Economics Case Study / Journal Bearing Design Case Study / Metal Casting Hemispherical Top Cylindrical Side Riser\\Case Study / Liquefied Petroleum Gas (LPG) Cylinders Case Study / Material Removal/Metal Cutting Economics with Two Constraints / The Open Cargo Shipping Box with Skids / Profit Maximization Considering Decreasing Cost Functions of Inventory Policy / Summary and Future Directions / Thesis and Dissertations on Geometric Programming