This book gives a comprehensive overview on the various aspects of Trichoderma, a filamentous fungus ubiquitously present in soil. Topics addressed are the biology, diversity, taxonomy, ecology, biotechnology and cultivation of Trichoderma, to just name a few. Basic as well as applied aspects are covered and a special focus is given on use of Trichoderma in agriculture and beyond. Trichoderma species are widely distributed throughout the world in soil, rotting plant material, and wood. Although they are often considered as a contaminants, Trichoderma species are also known for their ability to act as biocontrol agents against various plant pathogens and plant diseases, and also as biostimulants promoting plant growth.