It is quite surprising to me that there hasn't really been any utilities for editing the original arcade versions of Pac-Man and Ms. Pac-Man that are readily available and easy to use. I know they exist, but they usually require DOS, which is much more difficult to use than with standard Windows, and some of these don't work in computers running 64bit Windows.
I was hoping someone would be able to create an easy to boot and use editor in the same style as the editor featured in Champ Ms. Pac-Em, an obscure recreation of Ms. Pac-Man, that allows one to open the level files in a Pac-Man/Ms. Pac/Pac Plus rom and edit them by drawing the maze walls and pellets (either by the easier "add walls" feature from Champ Ms. Pac-Em or via the advanced tile placer), defining the maze(s)' main color scheme from the available palettes (allowing results similar to these: http://www.donhodges.com/images/mspac/ms_pacman_wierd_colors.gif
.), edit the color palettes from the selection of thirteen colors (an additional four if editing Pac-Man Plus), and a "mirror" function. It should also allow one to edit the graphics by opening it's respective file.
EDIT: It may be worth mentioning that with Ms. Pac-Man, the fruit paths could be drawn automatically based on how the walls are laid out, but can be defined by the user. Also modifying the number of pellets required to finish a board.