BusyBox "The Swiss Army Knife of Embedded Linux" is a multiuse-utility, designed for embedded Linux-systems:
- BusyBox combines tiny versions of many common UNIX utilities into a single small executable.
- It provides replacements for most of the utilities you usually find in GNU fileutils, shellutils, etc.
A working system may consist of just a Linux kernel, some device nodes in /dev, a few configuration files in /etc, BusyBox, and maybe a bootmanager.
For example, BusyBox is used in Tiny Core Linux.
BusyBox can provide most of the functionality of the many programs typical found in /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin, all in a single binary, thus saving space on small systems.
As a shell, BusyBox provides ash.
As a calculator, BusyBox provides dc, a "Tiny RPN calculator".
BusyBox can be configured (at compile-time) to include as little or as much "applets" as needed/desired.