Technical Abstract: Biosurfactants are surfactants whose common feature is biodegradability, which provides them with a major advantage over the majority of surfactants currently in the market. Biosurfactants are produced from a wide range of raw materials, and manufactured using chemical, enzymatic, microbial, and a combination of synthetic methods. Biosurfactants are applied in a variety of products including those used in agriculture (crop protection); foods (additives, processing, preserving, etc.), cosmetics/body care (skin, hair, oral, etc.), medical (antibiotic, anti-tumor, gene therapy, etc.), petroleum (enhanced oil recovery), cleaning (dishwashing and laundary detergents), remediation (contaminated soil, water, beach, etc.). In this chapter, biosurfactants are grouped into two broad categories and discussed. Biosurfactants synthesized from small molecules such as: mono- and di-saccharides, lipids, amino acids, and their combinations are discussed first. Biosurfactants based on farm-based biopolymers such as starches, plant proteins, and vegetable oils are discussed next. Examples of synthesis, structures, and applications of major categories of biosurfactant are given. The surface energies and polarities of farm-based biosurfactants are estimated from analysis of their surface and interfacial properties using existing surface energy models.