1. An implementation of the AT&T Plan 9 shell. rc is a command interpreter and programming language similar to sh(1). It is based on the AT&T Plan 9 shell of the same name. The shell offers a C-like syntax (much more so than the C shell), and a powerful mechanism for manipulating variables. It is reasonably small and reasonably fast, especially when compared to contemporary shells. Its use is intended to be interactive, but the language lends itself well to scripts. From Debian 3.0r0 APT

2. r mode for wasting time This package contains a glamorous and ultimate major mode for Emacs. IRC in a box. Make your IRC client able to act as editor, too. This is what modern net addicts were searching for. From Debian 3.0r0 APT