Pear Linux 6, code-named Bartlett, is the latest release of Pear Linux, or Pear OS, a desktop distribution based on Ubuntu Desktop. Unlike its parent distribution, which uses the Unity Desktop, Pear Linux features a custom GNOME Shell called Pear Shell.
Pear Linux 6 is based on Ubuntu 12.04, and features many new and cool features. In fact, the version of Pear Shell that comes with Pear Linux 6 is a near-complete overhaul of the edition in Pear Linux 5. And by my assessment, it is probably the best GNOME Shell adaptation available. It is most definitely better than the stock GNOME Shell.