Rhino Linux had been in beta for several months for this Ubuntu rolling release that evolved from the earlier Rolling Rhino Remix distribution. In addition to being a rolling release flavor, further differentiating it from upstream Ubuntu is that it uses Pacstall as an AUR-like package manager for Ubuntu. Rhino Linux also uses the "Unicorn Desktop" as its blend of the Xfce desktop environment. Rhino Linux also prides itself in using "sane default" and strives for a better user experience.
I haven't experimented with Rhino Linux myself yet but a number of Phoronix readers have expressed interest in this Ubuntu rolling-release effort. For downloads or to learn more about this new Linux distribution effort, see RhinoLinux.org .