You need more desktop space but don't have the possibility to add more monitors? This is the perfect program for you. When you push your mouse cursor to the left or right border of your screen you will see that your windows simply scroll to the opposite direction creating more space for having many windows open next to each other.
There is an auto arrange option that automatically orders all you windows nicely next to each other and you can limit the virtual desktop space to the space that is used by your open windows so you don't get lost. Also you can open the overview display so you can see your whole extended virtual desktop. If you have specific tools on your desktop that you don't want to scroll then you can exclude them from the scrolling windows list.