Description:

BusyBox combines tiny versions of many common UNIX utilities into a single
small executable. It provides minimalist replacements for most of the utilities
you usually find in GNU fileutils, shellutils, etc. The utilities in BusyBox
generally have fewer options than their full-featured GNU cousins; however, the
options that are included provide the expected functionality and behave very
much like their GNU counterparts. BusyBox provides a fairly complete POSIX
environment for any small or embedded system.

BusyBox has been written with size-optimization and limited resources in mind.
It is also extremely modular so you can easily include or exclude commands (or
features) at compile time. This makes it easy to customize your embedded
systems. To create a working system, just add /dev, /etc, and a kernel.