  We report recent progress on understanding the thermalization of the
quark-gluon plasma during the early stage in a heavy ion collision. The
initially high overpopulation in the far-from-equilibrium gluonic matter
("Glasma") is shown to play a crucial role. The strongly interacting nature
(and thus fast evolution) naturally arises as an {\em emergent property} of
this pre-equilibrium matter where the intrinsic coupling is weak but the highly
occupied gluon states coherently amplify the scattering. A possible transient
Bose-Einstein Condensate is argued to form dynamically on a rather general
ground. We develop a kinetic approach for describing its evolution toward
thermalization, and based on that we find approximate scaling solutions as well
as numerically study the onset of condensation.
