Emacs
22 Lisp Reference Manual:</p>
Appendix A Emacs 21 Antinews
For those users who live backwards in time, here is information
about downgrading to Emacs version 21.4. We hope you will enjoy
the greater simplicity that results from the absence of many
Emacs 22.1 features.
A.1 Old Lisp Features in Emacs 21
- Many unnecessary features of redisplay have been
eliminated. (The earlier major release, Emacs 20, will have a
completely rewritten redisplay engine, which will be even
simpler.)