An overview is given of additives and modifiers of biopolymers. Engineering properties of biopolymers are explained. Insight into processing technologies of biopolymers is given: extrusion, mixing and compounding, reactive extrusion, injection moulding, film extrusion, thermoforming, blow moulding, compression moulding, lamination and fibre spinning, including electrospinning. Relations between the processing technologies, biopolymer types and applications are explained. Biopolymer based product development and design is explained by case studies and industry practices. Environmental aspects of biopolymers processing and applications as recycling and circular economy, eco-design and life cycle analysis are explained. Introduction to international policies and regulatory framework of biopolymers is given.