reb-mode
reb-mode is an interactive compiled Lisp function in `re-builder.el'.
(reb-mode)
Major mode for interactively building Regular Expressions.
This mode runs the hook `reb-mode-hook', as the final step
during initialization.
key             binding
---             -------
C-c		Prefix Command
C-c C-b		reb-change-target-buffer
C-c C-c		reb-toggle-case
C-c C-e		reb-enter-subexp-mode
C-c TAB		reb-change-syntax
C-c C-q		reb-quit
C-c C-r		reb-prev-match
C-c C-s		reb-next-match
C-c C-u		reb-force-update
C-c C-w		reb-copy