  Recently, the numerical solution of multi-frequency, highly-oscillatory
Hamiltonian problems has been attacked by using Hamiltonian Boundary Value
Methods (HBVMs) as spectral methods in time. When the problem derives from the
space semi- discretization of (possibly Hamiltonian) partial differential
equations (PDEs), the resulting problem may be stiffly-oscillatory, rather than
highly-oscillatory. In such a case, a different implementation of the methods
is needed, in order to gain the maximum efficiency.
