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

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.