command-not-found.com

A documentation system for various programming languages. More information: <http://www.doxygen.nl>.

Run command or interactive shell with special root directory. More information: <https://www.gnu.org/software/coreutils/chroot>.

apt-key

Key management utility for the APT Package Manager on Debian and Ubuntu. Note: apt-key is now deprecated (except for the use of apt-key del in maintainer scripts). More information: <https://manpages.debian.org/latest/apt/apt-key.8.html>.

nmon

A system administrator, tuner, and benchmark tool. More information: <https://manned.org/nmon>.

salt

Execute commands and assert state on remote salt minions. More information: <https://docs.saltproject.io/en/latest/ref/cli/index.html>.

composer

A package-based dependency manager for PHP projects. More information: <https://getcomposer.org/>.

phpmd

A PHP mess detector that checks for common potential problems. More information: <https://github.com/phpmd/phpmd>.

Display an overview of the filesystem disk space usage. More information: <https://manned.org/df.1posix>.