ESS has been tested with

  * S-PLUS 3.3, 3.4, 4.5, 2000, 5.0, 5.1, 6.0, 6.1, 6.2

  * R >=0.49

  * S4

  * SAS >=6.12

  * BUGS 0.5, 0.603

  * Stata >=6.0

  * XLispStat >=3.50

on the following platforms

  * Linux (all)

  * Solaris/SunOS (all)

  * Microsoft Windows 95/98/NT/2000/XP (SPLUS 4.5/2000/6.*, R, SAS and BUGS)

  * 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, 21.3

  * XEmacs 21.0, 21.1.13-14, 21.4.0-8, 21.4.9-13/21.5.17 (requires the files.el patch to revert-buffer for the Local Variables updating problem), 21.4.14-15; as of June 2004, ESS does not work with XEmacs Betas such as 21.5.17

  * GNU Emacs <20.3 and XEmacs <21.0 (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.  Also, note that the `custom' library bundled with Emacs 19.34 is too _old_, its API is incompatible with the `new custom' bundled with recent Emacsen. The `new custom' for Emacs 19.34 is available for download here (ftp://ftp.dina.kvl.dk/pub/Staff/Per.Abrahamsen/custom/custom-1.9962.tar.gz).)