With a few lines of self-written firmware and a simple Perl script, Perlmeister Mike Schilli trains one of his Linux computers with a plugged in Arduino board to switch electrical equipment on and off using a relay. Enchanting.
When the Perlmeister is on the road, he likes to know what's going on at home. Armed with just two scripts, he draws on the Tumblr API to store snapshots cyclically from his home security camera.
It started off harmlessly enough with a few funny pictures of cats, but eventually it became the Internet phenomenon par excellence. It's no joke: Perl gives you some great tools for building and customizing memes yourself.
Your favorite office suites have a surprisingly active life at the command line, and various supplementary scripts can help you perform some functions more easily there than on the desktop.
SysV init was formerly the sole candidate for starting processes on Linux, but today, a tech-savvy generation of init systems is waiting in the starting blocks.