Divided into different sections featuring alginates, carrageenans, cellulose, starch, chitin, chitosan, gums, etc, each chapter presents chemical, physical, and biological attributes, and reviews the recent research performed such as drug carriers, selective water absorption materials from oil-water emulsions, purification of water, biomedical applications, etc. The authors hope that this brief will help to inspire scientists towards novel sources for chemicals, materials, and energy in the years to come.