9. A computer system for rendering graphics for display on a display screen, the computer system comprising: at least one processing unit; and at least one memory communicatively coupled to the at least one processing unit and storing computer readable instructions that when executed by the at least one processor perform a method, comprising: receiving selection of a first graphic definition for rendering a first graphical hierarchical diagram, the first graphic definition specifying a first graphical element; in response to the selection of the first graphic definition, rendering the first graphical element within the first graphical hierarchical diagram in a drawing pane on the display device; receiving content text within the first graphical element; receiving a first customization to a presentation property of the first graphical element; updating the presentation property of the first graphical element with the first customization; receiving a second customization to a semantic property of the first graphical element; updating the semantic property of the first graphical element with the second customization; receiving a selection of a second graphic definition; and in response to the selection of the second graphic definition, rendering a second graphical hierarchical diagram comprising a second graphical element that includes the content text and the updated semantic property but not the updated presentation property.
13. The computer system of claim 9 , wherein the first graphical element is a node, and wherein the node is a shape selected from the group consisting of: a circle, a square, a triangle, and a part of a shape.