From Greg's Shareware:
Aaron Light makes Mac OS 8 look more like Mac OS 8. Although Apple has updated the Macintosh user interface in Mac OS 8, many third party applications do not yet take full advantage of these changes. Aaron Light patches these applications to use the new appearance, giving your Macintosh a more uniform interface. In particular, Aaron Light patches progress bars (including the startup progress bar and some indeterminate progress bars or barber poles), floating windows, and dialog box backgrounds, as well as fixing a number of menu drawing glitches.