I will make an attempt to describe the scientic contributions of Paco Marcellán. This includes orthogonal
polynomials on Cassinians and lemniscates, modications of orthogonal polynomials, orthogonal polynomials
on the unit circle, semiclassical orthogonal polynomials, Sobolev orthogonal polynomials, linear
combinations of orthogonal polynomials, (quadratic, cubic) polynomial mappings, recurrence relations and
dierential equations, asymptotic behavior, zeros and electrostatics, etc. Special attention will be paid to
his pivotal role as a coordinator and public relations officer of orthogonal polynomials in Spain.