S15Pup is built from a "Puppy builder" system named Woof-CE (woof-CE at GitHub), which can build a Puppy Linux distribution from the binary packages of any other distro. Each "Puppy distro" built by Woof-CE is a distinctive distribution in its own right, with unique features. You choose a puppy based on your particular needs, be it specific hardware, software, or access to and compatibility with the package repositories of a particular major distro. S15Pup is built from Slackware-15.0 binary TXZ packages, hence has binary compatibility with Slackware and access to the Slackware and Salix repositories. It is available in both 64-bit and 32-bit versions.