Emerald is a cool window decorator application that will replace your default window decorator. There are many Emerald themes that you can select from as given in the link listed below, which will allow you to change the appearance of your windows (borders, menus, buttons, scrollbars, etc.).
Since Ubuntu 11.10, Emerald is no longer in the official repositories of Ubuntu. So, the solution is to install Emerald from source as described below.
To install Emerald (0.9.5) on Ubuntu 12.04 Precise Pangolin, open the terminal and install firstly these required dependencies:
sudo apt-get install build-essential git autoconf libtool libwnck1.0-cil-dev libwnck-dev intltool libdecoration0-dev
Install also CompizConfig Settings Manager with this command:
sudo apt-get install compizconfig-settings-manager compiz-fusion-plugins-extra compiz-fusion-plugins-main
Download and extract the Emerald package with these commands:
cd /tmp && wget -O emerald-0.9.5.tar.gz http://goo.gl/3liwk
tar -xf emerald-0.9.5* && cd emerald-0.9.5
Next, install Emerald with this sequence of commands:
sudo make install
To quickly enable Emerald, you can run this command:
emerald --replace &
Start now Emerald Theme Manager from the Unity Dash to start managing your Emerald themes. Emerald themes can be obtained from this link. If you want to start Emerald as the system starts, open CompizConfig Settings Manager and head to the Effects section and click Window Decoration:
In the Command field, replace:
Click the Back button and close the window. Emerald will now start automatically at system startup. If you want to disable this feature and restore default settings, press the reset button for the Command box, then log out and log back in: