apt
A commandline package manager and provides commands for searching and managing as well as querying information about packages.
awk
awk is a complete pattern scanning and processing language, it is most commonly used as a Unix command-line filter to reformat the output of other commands.
base64
base64 encode/decode data and print to standard output.
bzip2
a block-sorting file compressor.
chmod
Change file rights.
cron
daemon to execute scheduled commands.
curl
transfer a URL.
cut
remove sections from each line of files.
dig
DNS lookup.
file
determine file type.
find
search for files in a directory hierarchy.
ftp
File Tranfser Protocol.
gpg
OpenPGP encryption and signing tool.
grep
print lines matching a pattern.
gzip gunzip zcat
compress or expand files.
md5sum
compute and check MD5 message digest.
ntp
Network Time Protocol
rev
reverse lines characterwise.
scp
secure copy (remote file copy program).
sed
stream editor for filtering and transforming text.
showmount
showmount
sort
sort lines of text files.
strings
strings description.
tar
an archiving utility.
tmux
Who needs multiple separate terminals when you have tmux?
touch
change file timestamps.
tr
translate or delete characters.
uniq
report or omit repeated lines.
watch
watch description.
wc
print newline, word, and byte counts for each file.
xxd
make a hexdump or do the reverse.