What does this mod do?
It makes it easier for modders to check whether you have certain packs installed. This is done to integrate mods with packs while keeping them compatible with the base game.
Should I install this mod?
Only if you're using another mod that requires it (its creator should tell you). You only have to install it once.
What if I have every pack?
You still need to install this mod if using another that requires it. This script allows modders to write code that the game cannot understand on its own, so leaving this mod out can cause issues while loading their files.
More more information and alternate downloads, please read its webpage.