I bet there are some Adobe programmers reading HN; I don't think some rough estimates would be a violation of their NDA and I'd be curious to hear them, too.
You'd be surprised. While the code base has expanded on a geometric scale since 1.0 (we're now clocking in around 4-5M LOC), there are still routines that have survived all these years. While the implementation details have changed radically, a lot of the old architectural vestiges are going strong.
The more things have changed, the more they've stayed the same.
