When going gets tough, I go hacking...
Here are some cool packages that run under Emacs - I can't believe I've done
something useful!
Both packages are part of the standard distribution of
Emacs and
XEmacs.
Plan for Emacs Rescue,
PERil.
Viper is included in the standard distribution of Emacs 19.29 and XEmacs 19.12 and later. The above link points to the latest version of Viper, which might not work with older versions of X/Emacs.
You will not want (or need) to see a diff output ever again!
Ediff has been a standard part of Emacs since version 19.25 and of XEmacs since version 19.11. The link above points to the latest version, which requires the latest versions of Emacs and XEmacs.