The Emacs Interface was originally developed for GNU Emacs 19.34 and is presently being maintained using XEmacs 21.1 and tested with GNU Emacs 21.2. For best performance and compatibility and to enable all features we recommend that the latest versions of GNU Emacs or XEmacs be used. For information on obtaining GNU Emacs or XEmacs; see http://www.gnu.org/software/emacs/ and http://www.xemacs.org, respectively.