Selection (S key)
Allows you to select existing points to move or delete them in 2D view. Use the CTRL key to modify the selection
Brush (B key):
Allows you to add, move or delete a point in 2D view. To delete a point, maintain the SHIFT key and click on the point.
Tangent (T key):
Allows you to modify the tangents of a point. You can use the CTRL, SHIFT and/or ALT key to change the behavior of this tool. Right click on a point to reset his tangent in all views. To reset the tangent position in the current view only, hold the CTRL key. Double-click on the tool icon to reset all the tangents of the curve.
Zoom:
Allows you to change the scale of the current view. To fit the zoom on all points, double-click on the tool icon.
Notes (F2 key):
Allows you to write some information about the current curve (time, demo, action ...).