Try this applet to draw your own syntactic diagrams (java 1.1).
button << : go to the precedent rule.
button <in: to load a grammar from input window (errors are report in debug window)
clic on non-terminal: to explore the grammar.
at the begining the grammar is Java

(There exist some problems with the Java VM from Netscape on Macintosh! so ...)

BNF CLUB