ESS: Emacs Speaks Statistics
A Multiplatform, Multipackage Development Environment for Statistical Analysis.
ESS is a GNU Emacs and XEmacs mode for interactive statistical programming and data analysis. Languages supported: the S family (S, S-PLUS and R), SAS, BUGS/JAGS, Stata and XLispStat. ESS grew out of the desire for bug fixes and extensions to S-mode and SAS-mode as well as a consistent union of their features in one package.