May be fun to play with, but rather limited, as tools based on natural language tend to be.<p>For more flexible diagram work try the Artist-mode/ditaa combination (<a href="http://www.emacswiki.org/cgi-bin/wiki/ArtistMode" rel="nofollow">http://www.emacswiki.org/cgi-bin/wiki/ArtistMode</a>, <a href="http://ditaa.sourceforge.net" rel="nofollow">http://ditaa.sourceforge.net</a>)<p>Or course once you get really serious you'd use Graphviz <a href="http://www.graphviz.org" rel="nofollow">http://www.graphviz.org</a><p>Diagrams in text = version controlled = win!