This is called a billing block:
You find it at the bottom of movie posters and often at the end of movie trailers. In an Op-Art piece from last year, Ben Schott explains how the billing block is carefully constructed with information from contracts and legal agreements.
The content, order and format of the billing block are governed by two things: personal service contracts with cast and crew, and industrywide agreements with professional guilds — notably the Directors Guild of America (D.G.A.) and the Writers Guild of America (W.G.A.). Thus, while some elements of the billing block remain consistent, others depend of the type of film and on individual negotiations. That said, there has been a marked inflation in billing block credits. An “Ocean’s 11” poster from 1960 credited just three noncast individuals; the 2001 remake poster credited, coincidentally, 11.