In 2007, when Prism was launched, there were some enthusiastic reviews about this application. Then the widget era began and Prism popularity decreased. Anyway, Prism is still a powerful application for all that people who desire to run their more often used web application saving RAM and CPU resources. Prism, based on XULRunner, is multi platform, easy to use and very flexible. To use it on Ubuntu you can launch the Terminal and type:

sudo apt-get install prism

or using the Synaptics Package Manager (System —> Administration —> Synaptics Package Manager). Then go to Applications —> Internet —> Prism and a small windows appears. Now, fill in all the required information: the web application URL, the name you prefer, settings and do not forget to click on the Desktop shortcut option. At this point you will find a new rough icon on your Desktop with the name you chose. The first time you use it, with the right mouse button click on it and go to Properties —> Permissions and Allow executing file as program. If you want to change the icon you have to click on it (with the right mouse button), go to Properties —> Basic and choose your favorite icon clicking the icon on the upper left corner. If all are steps are annoying for you, it is possible to use Prism as add-on for Firefox. In this case, on Firefox, go to Tools —> Add-ons —> Get Add-ons and type Prism on the search bar. You will install Prism as a simple add-on for Firefox. Now, you can automatically generate a Prism application just clicking on Tools —> Convert Website to  Application when you are in the web application page.

On Windows or MAC we suggest to download the standalone package directly from the official web page or install Prism as Firefox add-on following the same steps we described for Ubuntu. If you use the Prism standalone package you have to decompress it in your favorite location. For Windows users: when you set up a new Prism application, try the tray menu option but do not forget to click on the Desktop shortcut or you will not be able to find again the application after you close it.

In my experience, Prism is really useful with all the Google web applications, with Zoho services and Pandora. Try and enjoy it!