>The documentation doesn't list any limitations. Perhaps memory or other resources might eventually be a limit.
>
>I suggest you just write a test program yourself, opening the same form multiple times - up to what you think might be a practical limit; perhaps 100 or 1000 times.

I recall some Devcon session where someone opened up 500 forms or something like that, showing off some kind of cascading trick.

It's easy enough to test, anyway. This cascades 200 forms, and hits no limit:

for n = 1 to 200
 do form multitest
 multitest.top = multitest.top+n
 multitest.left = multitest.left+n
endfor

They get a litle sluggish instantiating after about 100 or so :-)

BTW, a CLEAR ALL afterward is interesting to watch, too...