Tile editor
A tile editor is a special graphics editor, designed for rom hacking. Usually it supports some graphics modes used in games consoles like NES, Gameboy, SNES, etc. You open any (binary) file that may contain graphics and if they are visible in any graphics format the tile editor supports, then they are editable as well. The most common and importand tile editors are Tile Layer Pro (runs in Windows) and Tile Molester (runs in Java Runtime Environment), both written by SnowBro. Tile Molester supports both modes 1 and 2 and currently is the only one that can edit the font of Kick off 2.
In the following example, you can see how the font is stored in the SNES game Arkanoid - DOH it again.
Tile Molester webpage: http://www.stud.ntnu.no/~kenth/tm