The most customizable GNU/Linux distribution: Gentoo, canceled the 2008.1 release due to a change on its factoring release phase. As shown in the “New release strategy to provide more current install media” posted by Gentoo:

In future releases, Gentoo will focus on a more back-to-basics approach that will give you up-to-date install media on a regular basis and make much better use of our human resources. We’re looking into automated weekly builds of the minimal CDs and stage tarballs as well as maybe an annual LiveCD release.

So, for a future major Gentoo release, please consider that it can be in annual term, but weekly builds will be available.

Gentoo is famous because the overall distribution can be configured before it be installed. This highly customizable environment is the perfect solution to everybody looking to take the highest optimization of software vs hardware.

Gentoo is more recommended to experienced GNU/Linux users, but, nowdays Gentoo’s live cd cans approach more Linux newbies adepts.