Quicktime component distribution

Hey,

I wonder if anyone could tell me what is the state of Apple's
component delivery for Quicktime. Is the only means of delivering a
third party Quicktime component through a download and install by the
user or is it possible to deliver and install components through
Quicktime itself either by a signed package of some sort of through a
database that Apple manages? Is there documentation somewhere on this
matter?

Thanks

Corvus