Gentoo Linux is a special flavored, meta-level Linux distribution focusing on modularity, extendability, customisation, and maintenance.
Extract from About Gentoo Linux:
We produce Gentoo Linux, a special flavor of Linux that can be automatically optimized and customized for just about any application or need. Extreme performance, configurability and a top-notch user and developer community are all hallmarks of the Gentoo experience.
Thanks to a technology called Portage, Gentoo Linux can become an ideal secure server, development workstation, professional desktop, gaming system, embedded solution or something else — whatever you need it to be. Because of its near-unlimited adaptability, we call Gentoo Linux a metadistribution.
There are many active and friendly users in the Gentoo community in different forums around the world.