EmacsClient allows one to open a file for editing in an already running Emacs. Because it doesn’t start a new Emacs instance at each invocation, you can set up EmacsClient as the default editor, e.g. in the environment variable EDITOR or VISUAL. EmacsClient is part of and works only in conjunction with GNU Emacs. The program GnuClient provides the corresponding functionality for XEmacs, but also w