ALICE, A Large Ion Collider Experiment, is the experiment at the CERN
LHC dedicated to the exploration of strongly-interacting matter under
extreme conditions of temperature and energy density. After recalling
the objectives of the heavy-ion scientific program, the present
knowledge on the properties on matter formed in heavy-ion collisions
at the LHC will be reviewed together with the unexpected results
obtained in high multiplicity proton-proton and proton-Lead
collisions. The perspectives of this program on the short and long
term will finally be discussed.