BusyBox is a small executable that allow Android (and other OSes) to use various common Unix/Linux commands and utilities. It was released in 1999 by Eric Andersen and originally developed by Bruce Perens in 1996. In Android, BusyBox is used to execute various Unix files and commands. The main disadvantage of BusyBox is that the utilities are striped down versions and provide less features than the originals.
BusyBox is not the only project that offers such functionality. XDA Senior Member alireza7991 created an alternative project that offers more commands than standard BusyBox. Currently, GNU CoreUtils on Android allows you to use 105 utilities, but 2 of them don’t work. It’s pretty impressive number, and it is growing.
The GNU Core Utils package is built with the Linaro toolchain in order to be optimized for the greatest performance. The utilities can be executed by adding cu at the beginning, and this was done to avoid conflicts with the current version of BusyBox. To test this set of tools, you need to have a relatively new phone compatible with the ARMv7 instruction set, as well as support for ARM NEON—and most modern SoCs other than the Tegra 2 support both. Your device must be also rooted and have a custom recovery installed.
To get more information regarding this project, make your way to the development thread. It’s still pretty early, but this project seems to be extremely interesting.