Might be old news, but there's a change in Firefox with  version 23.0.1:

If you want to use a local signed or unsigned applet (file://.../JmolAppletSigned.jar, for instance), then you need to set


since the default is true.  Something like the issue here:


Robert M. Hanson
Larson-Anderson Professor of Chemistry
St. Olaf College
Northfield, MN

If nature does not answer first what we want,
it is better to take what answer we get.

-- Josiah Willard Gibbs, Lecture XXX, Monday, February 5, 1900