ESS version 5.1.n (n >= 2) works best with either GNU Emacs version 20.3 or higher, or XEmacs version 20.0 or higher.  It has been most thoroughly tested with:

  * S-PLUS versions 3.3, 3.4, 4.5, 5.0, 5.1, 6

  * R versions >=0.49

  * S4

  * SAS 6.x, 7.x, 8.x

  * BUGS 0.5 or 0.603

  * Stata >=6.0

  * XLispStat versions >=3.50

on the following platforms

  * Solaris/SunOS (all)

  * SGI (all)

  * Linux (S-PLUS 5.0, 5.1, R, XLispStat, S4, Stata 6.0)

  * Microsoft Windows 95/98/NT/2000 (SPLUS 4.5 and 2000)

  * Apple Mac OS (SAS for OS 9 and X11 R for OS X)

with the following versions of emacs

  * GNU Emacs 20.3, 20.4, 20.5, 20.6, 20.7, 21.1

  * XEmacs 20.0, 20.4, 21.0, 21.1.13, 21.1.14, 21.4

  * XEmacs 19.14, 19.16 and GNU Emacs 19.28, 19.29, 19.34 (Note that you must have custom support.  It is available at Abraham's Custom Pkg (http://www.dina.kvl.dk/~abraham/custom/). These releases of emacs are no longer supported, so an upgrade is recommended if you plan to use ESS.  This is not to say that ESS will not work, but it will be up to the user to set it up on their own.  If you have GNU Emacs 19.29, you may get it to work after unpacking 19.29.tar.gz, see the installation instructions.)