There are a wide variety of text editors available on our system. They range from editors which are easy to learn but lack sophisticated features, such as pico, to more advanced editors such as vi, emacs, and nedit. The more advanced text editors tend to be more popular. The vi editor is an interactive screen-mode text editor widely used on Unix systems. GNU Emacs (emacs) is an extensible and readily customized screen-mode editor that includes full undo, automatic file backup, and many other powerful features. If you want a particular editor to be used as the default text editor by various applications, alter the lines setenv EDITOR editor_name and setenv VISUAL editor_name in your .cshrc file.