Re: Help with XPIs / JavaScript.

> But - XPIs that add a button to a toolbar, or modify a menu, *do*
> modify files within existing .jar file do they not?

No they don't.  (Correcting myself.)  On further examination, I was
unable to find any XPI that actually modified an existing file that
was located with a .jar archive.

Adding buttons to toolbars works by somehow (not quite sure of this
yet) creating an extra folder tree that is "used" in some manner by
Mozilla.

> If you didn't mind being platform-specific you could execute
> system commands or your own included zip utility to do the job.

I may, then, just live with being platform-specific.  Can you give me
an example of code in install.js that would issue a system command? 
(I haven't found such a beast yet.)

Sorry for the newbie questions here.