Here's a list of some random, useful commands and tools to use in the Command Line.
A quick little script for PHP that will grab all the links in a page and output them in a human-readable format. Nothing special, but useful.
curl is used in the command line or in scripts to transfer data. It is also used nearly everywhere: in cars, television sets, routers, printers, audio equipment, mobile phones, tablets, settop boxes, media players and is the internet transfer backbone for thousands of software applications affecting billions of humans daily.