The 'wp' directory contains all source code specific to AbiWord. There is one subdirectory per module.

Directory ap (AP)

Contains source code for application-specific portion of the cross-platform framework defined in src/af/xap and src/af/ev. This contains application key bindings, mouse bindings, menu layouts, and toolbar layouts. It contains the menu string tables. It contains the table of application functions to which events may be bound. It contains the code to manage the document window (rulers, scroll bars, and the actual document window itself).

Directory impexp (ImpExp)

Contains importers and exporters for various file formats.

Directory main (main)
Contains platform-specific source code for main().

Subdirectories below may have additional hierarchy to further break things down by module. However, eventually, source code should find itself in a directory which indicates the portability of the code within it. For example, cross-platform code should always be placed in a subdirectory called 'xp'. Win32-specific code should be in a subdirectory called 'win'.