plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BIE%2B%E3%82%BF%E3%82%A4%E3%83%88%E3%83%AB%E3%83%90%E3%83%BC%E3%81%ABURL%E8%A1%A8%E7%A4%BA%E3%81%95%E3%81%9B%E3%81%AA%E3%81%84%E3%81%AE%E3%81%AF
plugin=diff is not implemented.