  In this article we review the present status of alpha clustering in nuclear
systems. First of all, an important aspect is condensation in nuclear matter.
Second, the alpha container model, recently been proposed by
Tohsaki-Horiuchi-Schuck-Roepke (THSR), will be outlined and the ensuing
condensate aspect of the Hoyle state at 7.65 MeV in 12C will be investigated in
some detail. After 15 years since the proposal of the alpha condensation
concept a critical assessment of this idea will be given. Alpha gas states in
other nuclei like 16O and 13C will be considered. The THSR wave function can
also describe configurations of one alpha particle on top of a doubly magic
core. The cases of 20Ne and 212Po will be investigated.
