The Atlantic - An "Easter egg" is a hidden message or in-joke that software developers will sneak into whatever project they're working on.
There are plenty in OSX and Windows. We even found a few in Firefox, including a message from a gang of robots and an alternative 'About' page that predicts nothing less that global domination.
telnet towel.blinkenlights.nl
= the coolest easter egg of all time -Kanye voice.