This directory contains

  calculation: an implementation of a financial calculator, an
               amortization scheduler, and an expression parser.
  doc: various notes about design and the design documentation.
  engine: a directory containing a gui-independent accounting engine
  experimental: for experimental systems.
  gnome: most of the code for the gtk/gnome front end.
  guile: guile related code including g-wrap bits.
  optional: bits supported via ./configure --enable-* or --with-* args.
  pixmaps: various runtime images.
  quotes: code for downloading stock quotes.
  register: a directory containg the register object.
  scm: all of the scheme code.

This directory contains a smatttering of gui-independent files.

  Destroy.[ch]      -- functions for destroying GUI windows
  EuroUtils.[ch]    -- implements euro currency conversions
  FileBox.h         -- generic interface to a file picker dialog
  FileDialog.[ch]   -- GUI independent functions for saving and loading
                       GnuCash files. The name of the file is rather
                       misleading!
  MainWindow.h      -- generic interface to main GUI window
  MultiLedger.[ch]  -- utilities for handling and updating multiple
                       register windows
  Refresh.[ch]      -- utilities for refreshing GUI windows
  SplitLedger.[ch]  -- loads a register window with data from the engine

  file-history.h    -- interface for saving and restoring file open history
  gnc-ui-common.h   -- define some GUI abstractions
  messages.h
  messages_i18n.h   -- translatable strings
  top-level.h       -- generic top-level interfaces
  ui-callbacks.h    -- an interface that any gnucash gui must support
