  The complexity measures of the Cr\'amer-Rao, Fisher-Shannon and LMC
(L\'opez-Ruiz, Mancini and Calvet) types of the Rakhmanov probability density
$\rho_n(x)=\omega(x) p_n^2(x)$ of the polynomials $p_n(x)$ orthogonal with
respect to the weight function $\omega(x)$, $x\in (a,b)$, are used to quantify
various two-fold facets of the spreading of the Hermite, Laguerre and Jacobi
systems all over their corresponding orthogonality intervals in both analytical
and computational ways. Their explicit (Cr\'amer-Rao) and asymptotical
(Fisher-Shannon, LMC) values are given for the three systems of orthogonal
polynomials. Then, these complexity-type mathematical quantities are
numerically examined in terms of the polynomial's degree $n$ and the parameters
which characterize the weight function. Finally, several open problems about
the generalised hypergeometric functions of Lauricella and Srivastava-Daoust
types, as well as on the asymptotics of weighted $L_q$-norms of Laguerre and
Jacobi polynomials are pointed out.
