This book highlights the latest findings on fundamental aspects of composting, the interaction of various microorganisms, and the underlying mechanisms. In addition to addressing modern tools and techniques used for composting research, it provides an overview of potential composting applications in both agriculture and environmental reclamation. Composting is the process of organic waste decomposition, mediated by microorganisms. The end-product is called ‘compost’ and can be used as a supplement to improve soil fertility. As the municipal waste generated in most developing countries contains a substantial amount of organic matter suitable for composting, this technology offers a win-win opportunity for stakeholders in terms of disposing of organic waste and providing organic fertilizers for agriculture. In addition, using compost reduces the dependency on harmful chemical fertilizers, and represents a sustainable and environmentally friendly alternative.