The photoelectron spectrum of ozone was reported 28 in 1974. Later, much higher resolution of the positions of vibronic peaks was obtained with pulsed-field-ionization zero-kineticenergy (PFI-ZEKE) spectroscopy . From the theory side, the vibronic photoelectron spectrum of ozone was modeled with a vibronic Hamiltonian parameterized using multi-reference configuration interaction method by Tarroni and Carter . Our contribution to this issue paying homage to the career and accomplishments of R.J.