Translations:FAQ/8/en
From Gentoo Wiki
Gentoo uses a BSD ports-like system called Portage - a package management system that allows great flexibility installing, maintaining, and updating software. Portage provides compile-time option support via USE flags, conditional dependencies, safe installation of software through sandboxing, use-case adaptable defaults thanks to system profiles, and configuration file protection - amongst many other features. All this functionality comes together to make Gentoo a very adaptable operating system, that can conveniently be tailored to any specific usage when needed, but when left in the default configuration will yield a simple, "sane default", environment.