system environment/shells
- bash - The GNU Bourne Again shell
- busybox - Statically linked binary providing simplified versions of system commands
- dash - Small and fast POSIX-compliant shell
- ksh - The Original ATT Korn Shell
- mc - User-friendly text console file manager and visual shell
- mksh - MirBSD enhanced version of the Korn Shell
- tcsh - An enhanced version of csh, the C shell
- zsh - A powerful interactive shell