Here is a list of all files with brief descriptions:

[detail level 123]

include
gutenprint
array.h	Array functions
bit-ops.h	Bit operations
channel.h	Channel functions
color.h	Color functions
curve-cache.h	Curve caching functions
curve.h	Curve functions
dither.h	Dither functions
gutenprint-intl-internal.h	Internationalisation functions
gutenprint-intl.h	Internationalisation functions
gutenprint-module.h	Gutenprint module header
gutenprint-version.h	Version functions
gutenprint.h	Gutenprint master header
image.h	Image functions
list.h	Generic list functions
module.h	Module functions
mxml.h	Mini-XML XML parsing functions
paper.h	Paper size functions
path.h	Simple directory path functions
printers.h	Printer functions
refcache.h	A simple reference cache
sequence.h	Sequence functions
string-list.h	String list functions
types.h	Gutenprint dimension type declarations
util.h	Utility functions
vars.h	Print job functions
weave.h	Softweave functions
xml.h	XML tree functions