Busybox (
BusyBox), is a set of command line tools which you can use to do a bunch of cool stuff with your phone with, although as an end user, you'll probably never see it. The installed apps cover everything from cat, to ed, to vi, to more, to mv, rm, mkdir, etc. etc. (Note that some of these were already in the shell). If you want to see it at work, either connect your phone to your computer, and start the adb shell, or in the market, download a console app. Once in the console, type busybox, and you should see a list of all the apps that are included in it. (Assuming you've rooted your device and put it on there).