reversible hexdump is a hexdump/hex2bin-toolkit that dumps to a special readable and reversible hexadecimal byte-dump, where you can not only change bytes, but also insert or delete bytes. It has a flush-switch, where it will output hexbytes for each single char it reads. This is especially useful (imho) for watching output from slow devices (e.g., serial devices like mice). The hex2bin-utility (the reverse-hexdump) not only accepts hexbytes for input, but also double-quoted strings with most of the escape-chars known from C and makes good attempts at undumping even hexdumps with repetition-lines (a "*" on its own line). It's written in ANSI C.