One of the best plugins for sliding panels, but …

… the style could be a bit more modern concerning for example the behaviour (jquery) and the opening/closing button.
But the extensive possibilities of settings are really gorgeous, especially that you can add your own custom widgets to this panel areas.

However the plugin has a big disadvantage:
as soon as you de-activate it (for example if you need to search for plugins conflicts), then all your custom settings, that you have made through the plugin’s option page, are lost for ever 🙁