awk = "Aho Weinberger and Kernighan"
This language was named by its authors, Al Aho, Peter Weinberger and Brian Kernighan.
grep = "Global Regular Expression Print"
grep comes from the ed command to print all lines matching a certain pattern g/re/p where "re" is a "regular expression".
rc (as in ".cshrc" or "/etc/rc") = "RunCom"
"rc" derives from "runcom", from the MIT CTSS system, ca. 1965. 'There was a facility that would execute a bunch of commands stored in a file; it was called "runcom" for "run commands", and the file began to be called "a runcom." "rc" in Unix is a fossil from that usage.'
Perl = "Practical Extraction and Report Language"
Perl = "Pathologically Eclectic Rubbish Lister"
The Perl language is Larry Wall's highly popular freely-available completely portable text, process, and file manipulation tool that bridges the gap between shell and C programming (or between doing it on the command line and pulling your hair out). For further information, see the Usenet newsgroup comp.lang.perl.misc.