  The multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method is
discussed and a fully general implementation for any number of layers based on
the recursive ML-MCTDH algorithm given by Manthe [J. Chem. Phys. {\bf 128},
164116 (2008)] is presented. The method is applied first to a generalized
Henon-Heiles (HH) Hamiltonian. For 6D HH the overhead of ML-MCTDH makes the
method slower than MCTDH, but for 18D HH ML-MCTDH starts to be competitive. We
report as well 1458D simulations of the HH Hamiltonian using a seven layer
scheme. The photoabsorption spectrum of pyrazine computed with the 24D
Hamiltonian of Raab {\em et. al.} [J. Chem. Phys. {\bf 110}, 936 (1999)]
provides a realistic molecular test case for the method. Quick and small
ML-MCTDH calculations needing a fraction of the time and resources of reference
MCTDH calculations provide already spectra with all the correct features.
Accepting slightly larger deviations, the calculation can be accelerated to
take only 7 minutes. When pushing the method towards convergence, results of
similar quality than the best available MCTDH benchmark, which is based on a
wavepacket with $4.6\times 10^7$ time-dependent coefficients, are obtained with
a much more compact wavefunction consisting of only $4.5\times 10^5$
coefficients and requiring a shorter computation time.
