New Long-Term-Supported Puppy
Precise Puppy is the new Long-Term-Supported release.
UPDATE (March 3, 2013) - New versions of WaryPuppy (for old PCs) and RacyPuppy (for new PCs) have been released - these are "home-grown" Puppies. See the updated Wary and Racy page.
March 10, 2013 - A version 5.5 update of Precise Puppy is now available. Precise Puppy 5.x is a new Puppy compatible with Ubuntu Precise Pangolin 12.04.2+ binary DEB packages (To read about the first Precise Puppy, see the first announcement by Barry Kauler). Precise Puppy will be a Long Term Supported release, following Ubuntu Precise Pangolin's LTS attribute. The kernel remains at 3.2.29 (this has many device drivers) and is PAE-enabled, so only high-RAM PCs may be able to boot Precise Puppy 5.5 (see below for non-PAE build).
For older machines like Pentium II that could not benefit from the high-memory capability of the standard Precise Puppy, get WaryPuppy.