In the 1980s, the upcoming of the first commercial pulsed EPR and ENDOR spectrometers in the X band frequency range, lead to a fast growth of the field. In the 1990s, parallel to the upcoming high-field EPR, pulsed EPR and ENDOR became a new fast advancing magnetic resonance spectroscopy tool and the first commercial pulsed EPR and ENDOR spectrometer at W band frequencies appeared on the market.