The aim of the work is to construct new polynomial systems, which are
solutions to certain functional equations which generalize the second-order
differential equations satisfied by the so called classical orthogonal
polynomial families of Jacobi, Laguerre, Hermite and Bessel. These functional
equations can be chosen to be of different type: fractional differential
equations, q-difference equations, etc, which converge to their respective
differential equations of the aforesaid classical orthogonal polynomials. In
addition to this, there exists a confluence of both the families of polynomials
constructed and the functional equations who approach to the classical families
of polynomials and second-order differential equations, respectivel