At present, shortcuts may vary or be non-functional for non-UK/US keyboards.
Moving around the map
Cursor keys to move one step at a time.
Page Up and Page Down to zoom in/out.
Editing
Click on a blank area to start a new line.
Double-click on a blank area to insert a new point of interest.
Esc to cancel an edit or a new line.
Z to undo.
When drawing a line:
↵ Enter to stop drawing a line.
⌦ Del to remove the previous point.
When a way is selected:
⇧ Shift+Click on this way to insert a new point.
Control+Click on another way to merge them, if they share an end-point. (Command/Apple key on a Mac.)
⇧ Shift+Click on the relation button to add the way to the last used relation.
⌦ Del to delete an entire way.
P to create parallel ways.
T to straighten a way - especially useful in grid systems. If used on a closed way, makes it into a smooth circle.
When a point is selected:
Click an end-point to extend the way.
X to split a way.
⌦ Del to delete a point.
- to remove a point from the current way only.
⇧ Shift+Click to start a new way from this point.
/ to select another way which shares this point (useful for ways 'hidden' under other ways).
Note: If using an internationalized keyboard, you might need to use the '/ or ÷ at the numeric keyboard. (And if you use a laptop you will perhaps need to press Fn-/ or Fn-÷ , usually printed in some color.)
K to lock or unlock a way/POI.
S to save your changes and add a commit message (if editing with save).
C to close the changeset (and add a commit message if editing live).