  It is shown that the hadron production in high energy pp, p{\bar p} and
e^+e^- collisions, calculated by assuming that particles originate in hadron
gas fireballs at thermal and partial chemical equilibrium, agrees very well
with the data. The temperature of the hadron gas fireballs, determined by
fitting hadron abundances, does not seem to depend on the centre of mass energy
and kind of reaction, having a nearly constant value of about 170 MeV. This
finding supports a universal hadronization mechanism in all kinds of reactions
consisting in a parton-hadron transition at critical values of temperature and
pressure.
