Here is the official announcement and release notes page:
Mick has also created a homepage for Slacko:
This is a thread on the Puppy Forum to provide feedback:
If you are interested in reading about development prior to the release of 5.5:
Comments:Posted on 6 Mar 2013, 15:36 by aarf
slacko55PAE not booting properly
getting various screen displays on non-boots of slacko55PAE which can be fixed only by ctrl+Alt+Backspace then xwin.
manual frugal with save file.
other wise it is fine with a 800x600 resolution.