Emerge is a graphical frontend to the UNIX “diff” and “diff3” commands. It is useful if two programmers on a project team both changed the same file and you need to integrate their changes.
Here is the Ediff manual section for emerge: http://www-2.cs.cmu.edu/cgi-bin/info2www?(emacs)Emerge
Also, you might want to set the “emerge-diff-options” variable to “--ignore-all-space”, so that emerge doesn’t waste your time by displaying differences in whitespace. You can do so by putting the following line in your ~/.emacs:
(setq emerge-diff-options "--ignore-all-space")
If you want to use emerge as git-mergetool, and want to start emacs using emacs -Q, then
#!/bin/sh emacs -Q $*
$ git config --global merge.tool emerge $ git config --global mergetool.emerge.path $HOME/bin/emerge-for-git
Now git-mergetool should start emacs using emacs -Q. I still don’t know how to use emacsclient for emerge.
But I have not tried integrating this with git yet.