  For Jacobi parameters belonging to one of the three classes: asymptotically
periodic, periodically modulated and the blend of these two, we study the
asymptotic behavior of the Christoffel functions and the scaling limits of the
Christoffel-Darboux kernel. We assume regularity of Jacobi parameters in terms
of the Stolz class. We emphasize that the first class only gives rise to
measures with compact supports.
