The latest version of this distribution can be downloaded from Softpedia
Macpup, a small, light OS that runs in RAM and it's very fast, featuring out-of-the-box functionality, with apps for office, graphics, multimedia, Internet, and much more, is now at version 550.Macpup 550, the newest E17 Macpup, is based on Precise Puppy 5.5.0, an official distribution that is fully binary-compatible with the Ubuntu 12.04 LTS (Precise Pangolin) packages.
This distribution contains all the applications found in Precise Puppy, with the addition of Mozilla Firefox 21, which is not exactly the latest one.
Macpup 550 also comes with the latest Enlightenment E17 window manager. The EFL libraries 1.7.5 and E17 version 170 were compiled and installed from source.
The developers have also advised users that this is a distribution for PCs and not intended for use on a real "Mac."
A complete changelog can be found in the official announcement. Download Macpup 550 right now from Softpedia.