An application lineup typically specifies what configuration of prerequisites and subapplications an application requires for a platform.

For example, an application lineup might specify that an application (AppA) contain three subapplications:

It also might specify that AppA name AppOS2 as a prerequisite for OS/2 systems and AppWin as a prerequisite for Windows systems.

An application can have one or more lineups. Each lineup matches one Smalltalk Boolean expression to a pair of configurations: one for the prerequisites that must exist in an image before the application can load, and one for the subapplications that must load into an image along with the application. The default lineup expression is true, meaning that prerequisites and subapplications (if any) are not platform-dependent.