Yes, we've been tinking about JavaScript too
No time to investigate further, but the idea was to get a random number and write out applet tag that takes that number as parameter. Or may be use DOM to access the applet tag.
It all depends on how ugly we're willing to make our sample HTML that the users will take as a template. Make it too complex, and nobody can use it. It's a well known fact that everybody smart enough to use our software is busy writing software for our competitors :)
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Less Is More. In my book, About Face, I introduce over 50 powerful design axioms. This is one of them.
--Alan Cooper. The Inmates Are Running the Asylum