Similar to syslog

Sleep (command)

System Management Interface Tool

Sort (Unix)

Source Code Control System

Strace

Strings (Unix)

Sudo

Tail (Unix)

Talk (software)

Tar (computing)

TCP Wrappers

Tcpdump

Time (Unix)

Tmux

Tomboy (software)

Tr (Unix)

Tty (Unix)

Tuxedo (software)

Uconv

Uname

Uniq

Unison (software)

Upstart (software)

Uptime

Uuencoding

Vi (text editor)

W (Unix)

Wait (command)