  In this contribution we briefly review some aspects of Lipatov's gauge
invariant QCD high energy effective action. The high energy effective provides
a field theory framework to systematically factorize QCD scattering amplitudes
and related theories in the limit of high center of mass energies. After a
short review of the underlying concepts, we address the question how the high
energy effective action can be used for actual calculations. As an explicit
example we review the derivation of the gluon Regge trajectory up to 2 loop. We
then review two topics of current interest: automatic amplitude generation of
high energy effective action amplitudes and a discussion of the relation
between the so-called Color-Glass-Condensate framework and the high energy
effective action.
