Phenolic Based Foams: State of the Art, New Challenges and Opportunities.- Introduction on Foam Manufacture.- Materials and Chemistry of Phenolic Foams.- Hybrid Composite Foam: Effect of Hybrid Fillers on the Mechanical Properties of Phenolic Foams.- Toughened Phenolic Foams.- Phenolic Syntactic Foams: Low-density Composites for Structural and Thermostructural Applications.