Display lists may be redefined in OpenGL, but not edited. The lack of editing simplifies display list memory management on the server, eliminating the penalty that such management would incur. One display list may, however, invoke others. An effect similar to display list editing may thus be obtained by: (1) building a list that invokes a number of subordinate lists; (2) redefining the subordinate lists. This redefinition is possible on a fine grain: a subordinate display list may contain anything (even nothing), including just a single vertex or color command.
There is no automatic saving or restoring of modes associated with display list execution. (If desired, such saving and restoring may be performed explicitly by encapsulating the appropriate commands in the display list.) This allows the highest possible performance in executing a display list, since there is almost no overhead associated with its execution. It also simplifies controlling the modal behavior of display list hierarchies: only modes explicitly set are affected.
Lack of automatic modal behavior in display lists also has a disadvantage: it is difficult to execute display lists in parallel, since the modes set in one display list must be in effect before a following display list is executed. In OpenGL, display lists are generally not used for defining whole scenes or complex portions of scenes but rather for encapsulating groups of frequently repeated mode setting commands (describing a texture image, for instance) or commands describing simple geometry (the polygons approximating a torus, for instance).