When you are operating on several windows and want to do some compared things,it is convenient to quat tile windows,or tile windows vertically/horizontally with keyboard shortcuts.
X-tile is a gnome applet for your panel (or optionally a standalone application)that allows you to select a number of windows and tile them in different ways.
This is especially useful for comparing products in separate web pages,or for programmers refering to documentation as they are programming.

Install X-tile

Download the deb package and double click to install.
x-tile_1.3.1-1_all.deb
You’d better to use this command to install X-tile(open terminal from Applications->Accessories menu to type command),because it may prompts you to install some dependences.

sudo dpkg -i x-tile_1.3.1-1_all.deb

When I first install x-tile,I need to install python-psutil by following command and then run previous command to install again.

sudo apt-get install python-psutil

Create keyboard shortcuts to quick tile windows in different ways

After installation,you can do this tile things with GUI by open X-tile from Applications->Accessories menu.
tile_windows

However,it’d better to create shortcuts rather than click icons.
Go to System->Preferences->Keyboard shortcuts to open following screen.Click Add,type a name as you like and type following commands:

x-tile –tile-all-vertically (skip main window, directly tile all opened windows vertically)
x-tile –tile-all-horizontally (skip main window, directly tile all opened windows horizontally)
x-tile –tile-all-quad (skip main window, directly quad tile all opened windows)
x-tile –maximize-all (skip main window, directly maximize all opened windows)

tile_windows1

In the screen,I create 4 shortcuts.Single click on right of the highlight line and set its key combination.

More:http://open.vitaminap.it/en/x_tile.htm