[Core model]
../synfigapp/main - stores information for the entire application (fg/bg colors, width, settings, input devices)

../synfigapp/instance - information unique for each instance (root canvas, canvas interface list, selection manager, save/save_as)

../synfigapp/canvas_interface - information unique to each exported canvas (I believe opening a canvas in the canvas browser loads a new interface, but not a new instance)
;* current time (at playhead), editing mode (normal/animated)
;* wrappers for various actions, such as adding layers or adding/setting/converting valuenodes

../synfigapp/value_desc - link to a value node (eg. layer.param_name parent_value_node.param_index; animated.waypoint; canvas.param)
valuelink - (?) Valuebase link. Inherits from synfig-core, why is this in studio/gtkmm?

../synfigapp/inputdevice - input devices
../synfigapp/settings - settings
../synfigapp/selectionmanager (look-into) - selection manager interface, null selection manager
../synfigapp/editmode - edit mode (normal, animated)
../synfigapp/uimanager - interface class for a UI interface (Dialogs such as yes_no, yes_no_cancel, etc) The actual UI interface used is defined elsewhere


[Action system]
../synfigapp/action - defines types of actions: action, undoable, canvasspecific, super, group
../synfigapp/action_param - defines parameters for action
../synfigapp/action_system - action system and passive grouper
../synfigapp/actions/* - individual actions

[======================= MISC =======================]

../synfigapp/general.h, general.h - gettext macros
../synfigapp/cvs - cvs system
../synfigapp/timegather - (?)

[======================== UI ========================]

[Core UI]
main - entry point, creates an instance of App
app - initializes the application (loads all UI components)
;* manages instances (which one is selected), canvas views, preferences
autorecover - automatic recovery (references app, uses instance)
devicetracker: save/load preferences and init extended input devices
instance - (?) inherits from synfigapp::Instance

[Misc UI]
splash - splash screen window
about - about dialog
adjust_window - (?) Adjustment Window, uses scale factor
onemoment - window saying "one moment, please"
dialog_setup
widget_filename
iconcontroller - pairs icon files with gtk names. Can get an icon for a valuenode or layer

[Canvas view]
canvasview - makes the menus; receives on_duck_changed events; creates a workarea

framedial - a table with play/forward/backward buttons
keyframedial - buttons for seek next, previous, lock
resolutiondial - Increase/decrease/ use low res
toggleducksdial - Show/hide various types of ducks
zoomdial - zoom in/out/etc

[================== Ducks and Tools =================]

[Workarea]
workarea - [inherits from duckmatic and Gtk::Table] the workarea
event_layerclick - event for layer clicked
event_mouse - stores the mouse button pressed and any modifier keys
eventkey - key of events (e.g. refresh, stop, undo, workarea clicked...)

[Ducks]
duckmatic - manages ducks, ducks_dragger, strokes, and Beziers
;* (Also defines duckdrag_base and translate)
;* When a duck drag is done, passes the new locations of the duck to canvasview (reverse manipulation function)

duck - a duck (stores either a point or an angle of rotation)
ducktransform_* - define duck transformations. These are used to transform the ducks so they line up with a transformed object on-screen

[Toolbox]
toolbox.h - the toolbox
widget_defaults - the fill/outline/etc selection widget in the toolbox
widget_tooloptions

[State system]
smach.h - typedef etl::smach<CanvasView,EventKey> Smach; // [state machine]
statemanager -keep track of states
state_* - all of the states
;* states such as normal and rotate define their own duck draggers
../synfigapp/blineconvert - used by draw tool to convert list of points to a bline

[================ Docks and Dialogs =================]
[Docks System]
dockmanager - gets size, position, or contents of a dockable, registers/unregisters dockables, find dockable or DockDialog, present a given dockable (takes a name)

dockable - generic class for dockables. "dnd" is "drag-and-drop"
dockbook - a notebook (tabbed group) of docks
dockdialog - a window, presumably  containing various dockbooks (tabbed groups) of dockables
dock_canvasspecific - base class for canvas-specific dockables

[Docks]
dock_info - (shows mouse position and the color under it)
dock_navigator
dock_history

dock_curves - uses curves widget + some time sliders
widget_curves

[Tree docks]
canvastreestore- (?)

dock_canvases - canvas browser

dock_timetrack
widget_timeslider - the time track, labeled at regular intervals
dialog_keyframe
dialog_waypoint
widget_keyframe_list
widget_waypoint
widget_waypointmodel
keyframeactionmanager - "Add new keyframe" and "keyframe properties" buttons, keeps track of keyframe tree
keyframetree - TreeView of keyframes
keyframetreestore - stores keyframes (is there any point to keyframe_tree_store_class_?)

dock_metadata
metadatatreestore - model for metadata tree

dock_layergroups
layergrouptree - TreeView of layer groups
layergrouptreestore - model for layer group tree

dock_children
childrentree - TreeView of canvas' children
childrentreestore - model for children tree

dock_layers
dock_params
layerparamtreestore - model for layer params tree
layertreestore - model for layers tree
layertree - returns TreeViews of layers and params
layeractionmanager - keeps track of layer tree; creates actions relating to layers

[Widgets for valuenodes]
widget_value - picks the right widget for a valuenode

widget_canvaschooser - Canvas valuenode (select canvas)
widget_color
widget_coloredit
widget_gradient - gradient valuenode
widget_compselect - select the composition (file) being edited
widget_distance - spinbutton (for type real when it's a distance)
widget_enum - enum type values
widget_time - time valuenode
widget_vector - (aka point)

[Dialogs]
dialog_color - select a color
dialog_gradient -set a gradient
canvasoptions -toggles grid snapping, visibility, and size
canvasproperties - name, id, info, and metadata

[======================= Other ======================]

[Renderer system] - I have not looked into this much
asyncrenderer
preview - Preview class and the preview widget
renddesc - RendDesc widget (Render menu - why is it called desc?)
renderer_* - rendering system
workarearenderer
dialog_preview
dialog_targetparam - parameters for rendering target

[Audio system] - Did not look at, as it is disabled
audiocontainer
dialog_soundselect
widget_sound

[Modules]
./mod_mirror/ - Mirror tool
./mod_palette/ - Palette
module - interface class for models: has methods start() stop()

[======================= MISC =======================]

ipc - (?)
keymapsettings - (Defines the structures for managing key map settings) affects accelerators

groupactionmanager - (look-into) references LayerGroupTree

compview - Does not appear to be used anywhere