1. (run commands) The filename extension common to many Unix configuration files, e.g. .newsrc, .cshrc, .twmrc, elmrc, etc. The suffix "rc" derives from a script-creation utility in CTSS called "runcom" (for "run commands"). Unix FAQ (https://cis.ohio-state.edu/hypertext/faq/usenet/unix-faq/faq/top.html). 2. A shell from AT&T's Plan 9, by Tom Duff. rc offers much the same capabilities as a traditional Bourne shell, but with a much cleaner syntax. An open source reimplementation was made by Byron Rakitzis, and is now maintained by Tim Goodwin . Latest version: 1.6, as of 2000-06-15. (https://star.le.ac.uk/~tjg/rc). (2000-06-17)