Dantzig-Wolfe decomposition and column generation,
devised for linear programs, is a success story in
large scale integer programming. We outline and
relate the approaches, and survey mainly recent
contributions, not yet found in textbooks. We
emphasize the growing understanding of the dual
point of view, which has brought considerable
progress to the column generation theory and
practice. It stimulated careful initializations,
sophisticated solution techniques for the restricted
master problem and subproblem, as well as better
overall performance. Thus, the dual perspective is
an ever recurring concept in our selected topics.