To improve the interoperability of your GNOME desktop, you can configure the default Web browser, mail reader, and terminal applications that are launched whenever another GNOME application needs these functionalities. To do this, click Applications+Utilities+Desktop+Preferred Applications.

On Web Browser, Mail Reader, or Terminal, select the name of the application to use as the default. For example, if you set your default browser to Firefox on Web Browser, Firefox is started when you click a link in an e-mail. You can also click Custom to customize the application's command. All settings made in Preferred Applications apply only to GNOME applications.