Hexedit	view and edit files in hexadecimal or in ASCII.
hexedit shows a file both in ASCII and in hexadecimal. 
The file can be a device as the file is not whole read. 
You can modify the file and search through it.
You have also copy&paste, and save to file functions.
Modifications are shown in bold.

WWW: http://www.chez.com/prigaux/hexedit.html
