A lot of terminal apps make use of the EDITOR= environment variable, however we don't define one in our default bash profile. For instace, when I had to use mutt for the first time to check email using a shell account, I tried to write a reply only to be dumped into a vi instance.
vi is a great text editor, however if you've never used it before it is incredibly difficult. It's not even obvious how to quit or get help without opening up a man page in another terminal. For those who prefer it, setting the EDITOR= line is a fairly simple task. As a reasonable default, however, nano is the way to go.
Developer comments
nano is the default editor in ubuntu.