Here's how you can install the Square icon set in Ubuntu 13.10.
1. Open a terminal window.
2. Type in the following commands then hit Enter after each.
sudo add-apt-repository ppa:noobslab/icons2
sudo apt-get update
sudo apt-get install square-icons
There are plenty of cool icon sets available for Linux, But "Square" icon set which is new and just released few days back is new competitor of good looking icons. This icon set is compatible with Gnome/other desktops as well as KDE and it has more than 15,000 icons.More at Noobs Lab
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