Polyetheretherketone (PEEK) was first produced in 1978 in the UK laboratories of Imperial Chemical Industries. The polymer initially was conceived as a high temperature‐resistant, tough cable‐insulation material. However, since commercialization of the polymer in 1981, the combination of ease of processing and excellent thermal stability and mechanical properties at high temperatures established PEEK as a general‐purpose molding and extrusion material in both natural and reinforced forms for high performance applications. KetaSripe and AvaSpire from Solvay and Victrex PEEK from Victrex are the commercial products available. The conventional processability of PEEK has resulted in a wide range of modified products incorporating glass, carbon or particulate fillers. Typical industries using the polymers are electrical, automotive, aerospace, chemical, medical, and engineering plastics to name a few.