The origin of the name "Guybrush" comes in part from Deluxe Paint, the tool used by the artists to create the character sprite. Since the character had no name at this point, the file was simply called "Guy". When the file was saved, Steve Purcell, the artist responsible for the sprite, added "brush" to the filename, indicating that it was the Deluxe Paint "brush file" for the "Guy" sprite. The file name was then "guybrush.bbm", so the developers eventually just started referring to this unnamed 'Guy' as "Guybrush"
Deluxe Paint 5 was the last release after Commodore's bankruptcy in 1994. But Dan Silva went on to join the Yost Group, which developed Autodesk's 3D Studio.