lde is a diskeditor for linux, originally written to help recover deleted files. It has a simple curses interface that was supposed to resemble an old version of Norton Disk Edit for DOS. Works well with ext2, minix, xiafs. Not so hot w/fat and iso9660
IMA2 Simple command-line editor of binary files (images, object filers, byte code, etc). More sofisticated that F4 option in FAR. More simple that GUI hex editors. Can be useed as command-line utility in scripts.