  We present some basic elements of the treatment of particle multiplicities in
jets from high energy collisions within perturbative QCD. Then we discuss the
universal features of the inclusive particle spectrum for the limiting case of
momentum p\to 0 (or p_T\to 0) as expected from soft QCD gluon bremsstrahlung.
The energy independence of the invariant particle density in this limit I_0=E
dN/d^3p|_{p\to 0} is predicted as well as the dependence of this quantity on
the the colour factors characteristic of the underlying partonic processes.
These properties are first recalled from e+e- collisions and then extended to
pp and nuclear collisions according to Ref. 1. Present data support these
predictions. It will be interesting to see whether new incoherent contributions
show up in the new energy regime of LHC.
