Shift		Ctrl		Alt

Rect Select		add		subtract	move sel
Ellipse Select		add		subtract	move sel
Free Select		add		subtract	move sel
Fuzzy Select		add		subtract	move sel
Color Select		add		subtract	
Iscissors		
Paths
ColorPicker		add to palette	pick fg/bg
Magnify					zoom in/out
Measure					15 deg.
Move			current/pick	move path	move sel
Crop			keep ratio	allow enlarge	crop/resize
Rotate					15 deg.
Scale					keep height	keep width
Shear
Perspective
Flip					horz/vert
Text
Bucket Fill		smilar/sel	fg/bg fill
Blend					15 deg.
Pencil			line		pick fg
Paintbrush		line		pick fg
Eraser			line		pick bg		anti erase
Airbrush		line		pick fg
Ink			line		pick fg
Clone			line		set src
Convolve		line		blur/sharpen
Smudge			line		
Dodge/Burn		line		dodge/burn