Inkscape

ACTION RESULT
Spacebar + LMB (Left Mouse Button) pan the canvas
CTRL+scroll wheel zoom the canvas
HELP > Key and Mouse Reference shortcut keys
CTRL+SHIFT+L open the layer panel
Selection Tool
drag the border move the object
CTRL+drag the border restrict movement horizontally or vertically
drag two-sided arrows resize the object
CTRL+drag two-sided arrows resize preserving the original height/width ratio
CTRL+SHIFT+drag two-sided arrows resize from the middle preserving the original height/width ratio
while the object is selected, click any border of the object change the resize handles to rotate handles
Drag the "cross mark" to desired position position the center of rotation
CTRL+SHIFT+click the "cross mark" put it back to the center of the object
CTRL+rotate restrict rotation to 15° angles
drag non-corner handles skew the object
CTRL+drag non-corner handles restrict skewing to 15° angles