Ymacs for Gmail bookmarklet allows you to replace standard text editor in Gmail with Ymacs - an Emacs-like editor (http://www.ymacs.org/).

How to use it

1. Create new bookmark and paste code from this file to url field.
2. Login to your Gmail account and start editing a new letter. Make sure to switch to "Plain Text" mode if you are in "Rich formatting" mode.
3. Click on the bookmark
4. Enjoy your new editor for Gmail