John the Ripper is a fast password cracker, currently available for many flavors of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. It supports several crypt(3) password hash types commonly found on Unix systems, as well as Windows LM hashes. On top of this, lots of other hashes and ciphers are added in the community-enhanced version (-jumbo), and some are added in John the Ripper Pro.
sdd is a replacement for a program called 'dd'. sdd is much faster than dd in cases where input block size (ibs) is not equal to the output block size (obs). Statistics are more easily understood than those from 'dd'. Timing available, -time option will print transfer speed Timing & Statistics available at any time with SIGQUIT (^\) Can seek on input and output Fast null input Fast null output. Support for the RMT (Remote Tape Server) protocol makes remote I/O fast and easy.
Change is a non-interactive text editor, similar to sed, but much easier to use. It works by substituting a specified target pattern in the source text with another specified text pattern. It can operate on multiple files specified on the command line, or it can operate upon stdin/stdout in filter mode.