AreaTree is an implementation of both the aXSL AreaTree module and the aXSL Galley module. In other words, it is suitable for use with XSL-FO processing systems that wish to push FO Tree data to an Area Tree. Once laid out, its contents can then be used as input to rendering systems that create output like PDF or PostScript. It is essentially a data structure. It keeps track of the relationship between parent and child nodes within itself, and also tracks the connections with the FoTree. It is responsible for computing the location of each Area on each page.