A link curvature processing module enables a user with the ability to control the curvature of links in a node-link diagram. As a node-link diagram is displayed to a user, the user may interact with the diagram and adjust the curvature of one or more links in the diagram to improve the readability of the diagram. The user's modification to the curvature of a link alters the shape of the link so that the position of the nodes connected to the link does not change. By providing the user with such control, the user is able to tailor the visual display of the links to the user's preference.