Long story short, the TLF library is implemented in actionscript. Said
library is hosted on adobe's servers.
In order to use the library, the player must have loaded it. The default
solution to this used by Flash is to wrap the main movie in a separate
This system is called RSL, or runtime shared libraries.
The preloader will load the embedded swf file (it uses the
DefineBinaryData swf tag for that) and the swz file. This is done
because otherwise you would get some nasty verify errors when the movie
tries to refer to a class that isn't defined at that point.
The effect is that your "main movie" is no longer the main movie,
removing luxuries like being able to use the stage before the
It also complicates the code for loading such a movie into another
movie. You have to get thru the preloader movie in order to access the
Luckily, this mess is solved for you by Adobe, use the SafeLoader class
that they have written. It will pretend to be a normal Loader that loads
a normal movie, letting you ignore the RSL preloader stuff.
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