The EMACS editor

emacs  (or xemacs)   to start editor
emacs filename   to start editor in an existing file

use arrow keys to move cursor

type to insert

backspace to delete

ctrl-v or page down   to page forward
alt-v or page up      to page backward

ctrl-g    deletes a command that is partially typed

ctrl-k   to delete from cursor to end of line

ctrl-space   to mark one end of text to delete
ctrl-w    to delete the text from the mark

ctrl-y    to insert the last deleted text or highlighted text
alt-y    to search through previous deletes and insert one of them

shift-ctrl -   to undo last edit command

join lines by putting cursor at beginning of line and then backspace

break lines by inserting a carriage return

ctrl-x ctrl-f filename   to open a file (either an existing file or a new one)
ctrl-x ctrl-s    to save the current file

alt-x recover file   to recover a previous editing session that crashed

ctrl-s pattern    to search forward for a pattern
ctrl-r pattern    to search backward for a pattern

ctrl-x ctrl-c    to exit emacs