ESS 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, 0.603

  * Stata >=6.0

  * XLispStat versions >=3.50

on the following platforms

  * Solaris/SunOS (all)

  * SGI (all)

  * Linux (S4, S-PLUS 5.x, R, XLispStat, 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 The Custom Library (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.  If you have GNU Emacs 19.29, see Unix installation.)