plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BIIS%2BIIS7.0%E5%A4%A7%E3%81%8D%E3%81%84%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB%E3%81%AE%E3%82%A2%E3%83%83%E3%83%97%E3%83%AD%E3%83%BC%E3%83%89
plugin=diff is not implemented.