for GIMP 2.8.7

I. GIMP Library
Functions not Related to Specific Images
Gimp — Main functions needed for building a GIMP plug-in. This header includes all other GIMP Library headers.
gimpenums — Enums and definitions.
gimpbuffer — Functions for manipulating cut buffers.
gimpcontext — Functions to manipulate a plug-in's context.
gimpgimprc — Interactions with settings from gimprc.
gimphelp — Loading help pages using gimp_help.
gimpmessage — Display a dialog box with a message.
gimpplugin — Functions useful for plugins, e.g. registration and progress indicators.
gimpproceduraldb — Functions for querying and changing procedural database (PDB) entries.
gimpprogress — Functions for embedding the progress bar into a plug-in's GUI.
Manupulating Images and their Properties
gimpchannel — Functions for manipulating channels.
gimpcolor — Functions for manipulating color.
gimpconvert — Conversions between RGB, indexed, and grayscale modes.
gimpdisplay — Functions to create, delete and flush displays (views) on an image.
gimpdrawable — Functions to manipulate drawables.
gimpdrawabletransform — Functions to perform transformatrions on drawables.
gimpedit — Edit menu functions (cut, copy, paste, clear, etc.)
gimpfileops — File operations (load, save, etc.)
gimpfloatingsel — Functions for removing or attaching floating selections.
gimpgrid — Functions manuipulating an image's grid.
gimpguides — Functions for manipulating guides.
gimpimage — Operations on complete images.
gimpimageselect — Modify the image's selection.
gimpitem — Functions to manipulate items.
gimpitemtransform — Functions to perform transformations on items.
gimplayer — Operations on a single layer.
gimppaths — Deprecated operations related to paths.
gimppixbuf — Get a thumbnail pixbuf for a drawable or image.
gimppixelfetcher — Functions for operating on pixel regions.
gimppixelrgn — Functions for operating on pixel regions.
gimpregioniterator — Functions to traverse a pixel regions.
gimpselection — Functions for manipulating selections.
gimptextlayer — Functions for querying and manipulating text layers.
gimptexttool — Functions for controlling the text tool.
gimptile — Functions for working with tiles.
gimppainttools — Access to toolbox paint tools.
gimpselectiontools — Access to toolbox selection tools.
gimptransformtools — Access to toolbox transform tools.
gimpundo — Control of undo/redo.
gimpvectors — Functions for querying and manipulating vectors.
Data Objects
gimpbrush — Functions operating on a single brush.
gimpbrushes — Functions for manipulating brushes.
gimpdynamics — Operations related to paint dynamics.
gimpfonts — Operations related to fonts.
gimpgradient — Functions operating on a single gradient.
gimpgradients — Operations related to gradients.
gimppalette — Functions operating on a single palette.
gimppalettes — Operations related to palettes.
gimppattern — Functions operating on a single pattern.
gimppatterns — Functions relating to patterns.
Controlling the Core's Selection Dialogs
GimpSelectButton — The base class of the data select buttons.
gimpbrushselectbutton — A button that pops up a brush selection dialog.
GimpFontSelectButton — A button which pops up a font selection dialog.
GimpGradientSelectButton — A button which pops up a gradient select dialog.
GimpPaletteSelect — A button which pops up a palette select dialog.
GimpPatternSelectButton — A button which pops up a pattern select dialog.
gimpbrushselect — Functions providing a brush selection dialog.
gimpfontselect — Functions providing a font selection dialog.
gimpgradientselect — Functions providing a gradient selection dialog.
gimppaletteselect — Functions providing a palette selection dialog.
gimppatternselect — Functions providing a pattern selection dialog.
II. GIMP User Interface Library
Object Hierarchy
gimpui — Common user interface functions. This header includes all other GIMP User Interface Library headers.
gimpexport — Export an image before it is saved.
GimpDrawablePreviewA widget providing a preview of a GimpDrawable.
GimpAspectPreview — A widget providing a preview with fixed aspect ratio.
GimpZoomPreview — A drawable preview with zooming capabilities.
GimpItemComboBox — Widgets providing popup menus of items.
GimpImageComboBox — A widget providing a popup menu of images.
GimpProgressBar — A widget providing a progress bar.
gimpmenu — Menus for selecting images, layers, channels and drawables.
gimpbrushmenu — A widget for selecting brushes.
gimpfontmenu — A widget for selecting fonts.
gimpgradientmenu — A widget for selecting gradients.
gimppalettemenu — A widget for selecting palettes.
gimppatternmenu — A widget for selecting patterns.
GimpProcBrowserDialog — The dialog for the procedure and plugin browsers.
GimpProcView — A widget showing information about a PDB procedure.
Index of new symbols in GIMP 2.2
Index of new symbols in GIMP 2.4
Index of new symbols in GIMP 2.6
Index of new symbols in GIMP 2.8
Index of deprecated symbols