The move to Gnome 3 and Unity has meant that many users found out the other Linux desktop environments, such as Xfce The default desktop environment of Xubuntu light and at the same time complete
Xubuntu / Xfce allow to have an environment very similar to the good old desktop Gnome 2 In fact we can customize the panels, add new widgets on them and other features that make it extremely versatile, while requiring very few resources.
Also used by users who have dated a PC or with scarce resources is an excellent alternative to Gnome Shell / Unity projects still very "young" with few customizations and above require significantly more resources.
Some readers have reported that notice Xubuntu just slightly especially if you have few resources available, the problem is due to the gestore window which is activated by display consists of default, which adds some effects to our desktop environment such as transparency of the panel, the shadows of the windows, etc.
Unfortunately, the composer brings you some nice effects, but if our PC is dated or scarce resources will notice a slight slow when using it.
However, we can simply disable this feature by going to Menu -> Settings -> Manager Settings and click on Adjustments of the window manager you start going out the window tab Composer and uncheck Enables the display composite.
Now we will have no effect, but our desktop will be much faster.