Shell Utilities

GNU Awk
Pattern scanning and processing language
Bzip2/Bunzip2, Gzip/Gunzip, Zip/Unzip
Compression/decompression tools 
Block sorting, GNU, and PK-ZIP
Less - the opposite of more
Scroll backwards 
Full regular expression searches 
Customizable key commands
GNU M4 Macro Processor
Many features not found in other M4 processors
GNU Shell Utilities
Typically faster, more portable versions of the standard shell utilities
basename, chroot, date, dirname, echo, env, expr, factor, false, groups, hostname, id, logname, nice, nohup, pathchk, printenv, printf, pwd, sed, seq, sleep, stty, tee, test, true, tty, uname, uptime, users, who, whoami