  In the last decade, it has been realized that the orbital angular momentum of
partons inside the nucleon plays a major role. It contributes significantly to
nucleon properties and is at the origin of many asymmetries observed in spin
physics. It is therefore of paramount importance to determine this quantity if
we want to understand the nucleon internal structure and experimental
observables. This triggered numerous discussions and controversies about the
proper definition of orbital angular momentum and its extraction from
experimental data. We summarize the present situation and discuss recent
developments in this field.

High Energy Physics - Phenomenology