Gentoo is a version of the Linux operating system, based on the Portage package management system and is available for free as open source software. Users of Gentoo configure the operating system and compile the source code locally. Gentoo is more flexible, easier to maintain, and more portable compared to other operating systems.
Gentoo was originally released on March 31, 2002 as version 1.0. As of March 8, 2011, it is up to version 11.0, and weekly updates are not uncommon. It can be installed from almost any Linux environment and typically requires an Internet connection, but it can be done without the Internet connection if necessary.