This theme contains graphics for customising corners and borders. It makes use of a technique described by Roger Johansson - see "customising_custom_corners_and_borders" However, the custom corners theme doesn't use all the JavaScript mentioned by Roger Johansson. Instead, divs are added when using the custom_corners_core_renderer (defined in renderers.php) instead of moodle_core renderer.
Note: Custom corners is included in Moodle 1.9 as an experimental feature.
Custom corners was created by Urs Hunkler, unodo.