This paper provides a general introduction to welding fundamentals (section 2) followed by sections on a few selected welding processes that have had significant developments or improvements over the last few years. The processes that are discussed are friction welding (section 3), hot plate welding (section 4), ultrasonic welding (section 5), laser/IR welding (section 6), RF welding (section 7) and hot gas/extrusion welding (section 8).