Mozilla prism is a framework for packaging web apps as applications. It uses the gecko rendering engine and is basically Firefox without the user interface. My reaction upon first reading about it a couple of years ago was as per the title – this is just a web browser with a restricted interface, and thus offered no advantage over a simple desktop url shortcut.

But there actually is a good reason to use prism, and that is privacy. Prism uses seperate profiles for each application, thus if you are logged in to Gmail, you do not have to be logged in while using Firefox and have Google track all your searches in addition to indexing your email. You can use Facebook in prism and not have to worry about third party sites accessing your profile, like the much-maligned beacon “service” facilitated recently.

In short prism affords a lot of convenience for those of us that like to keep their web identities segregated, but if you’re really really paranoid about privacy then Gmail and Facebook are two sites you probably shouldn’t use.

On Ubuntu you can install Gmail for Prism with the following command:

• aptitude install prism-google-mail

For Facebook:

• aptitude install prism-facebook

Once the prism package is installed you can also convert any site into a prism app by going to Tools > “Convert Website to Application”.