In this review paper we consider the polynuclear growth (PNG) model in one
spatial dimension and its relation to random matrix ensembles. For curved and
flat growth the scaling functions of the surface fluctuations coincide with
limit distribution functions coming from certain Gaussian ensembles of random
matrices. This connection can be explained via point processes associated to
the PNG model and the random matrices ensemble by an extension to the
multilayer PNG and multi-matrix models, respectively. We also explain other
models which are equivalent to the PNG model: directed polymers, the longest
increasing subsequence problem, Young tableaux, a directed percolation model,
kink-antikink gas, and Hammersley process.