Slackware for 64-bit hardware
Slackware has been officially ported to x86_64. The 64-bit variant of this venerable Linux distribution is being synchronised with the current traditional branch. Although many of the developers are already running Slackware64, the project will also be offering 64-bit architecture DVDs for sale, starting with the upcoming version 13. Slackware is probably the oldest Linux distribution that's still under active development, having been created in 1993.
As with Debian, its developers put the emphasis on stability and maturity rather than the latest features and program versions. The Slackware developers have thanked the unofficial 64 bit projects which they said took up the slack, and took the pressure off them, so they could take their time "getting everything just right" for the official release.