emerge
also: Portage
The package manager for Gentoo Linux that compiles and installs software from source code. It resolves dependencies, manages package versions, and handles system updates.
emerge is Gentoo's primary package management tool, built around the Portage package management system. Unlike binary package managers, emerge downloads source code and compiles packages on your system using your specific compiler flags and configuration options, optimizing software for your hardware.
The tool resolves complex dependency chains automatically and allows fine-grained control through USE flags—feature toggles that determine which optional features are compiled into packages. For example, emerge -av firefox shows what would be installed with verbose output before proceeding.
Common emerge operations include emerge --update --deep world to update your entire system, emerge --search keyword to find packages, and emerge --unmerge package to remove software. Emerge maintains detailed logs of installations and can rollback changes if needed.