  Violent nuclear collisions are open systems which require a non-equilibrium
description when the process should be followed from the first instants. The
heated system produced in the collision, can no more be treated within an
independent-particle picture and additional correlations should be taken into
account: they rely to in-medium dissipation and phase-space fluctuations. Their
interplay with the one-body collective behaviour activates the transport
dynamics: large-amplitude fluctuations and bifurcations in a variety of
mechanisms appear, from fusion to neck formation till eventually freezing out
the system into several intermediate-mass clusters. Starting from fundamental
concepts tested on nuclear matter, a microscopic description is built up to
address violent processes occurring in heavy-ion collisions at Fermi energies
and in spallation reactions, and it is applied to experimental observables.
