I remember back in the day there was supposedly a program that could scan a zone and tell you what loot mobs would drop before they were even killed. Is this still possible or is some loot not determined until the mob actually dies?

I know in some cases it should still work at least in theory, as some mobs will visibly wield the weapons they will drop. Anyway just wondering if such a program exists.

All you get now is appearance packets that set what graphic is in the mobs hand. The data is available but I don't know that it is mapped out.