So we can have
customized music, personalized notification popups, custom skins, titles, and capes, as well as many other features.
You don't need to install it, but to see/hear the new stuff, download it.
It is easy to install.
Download is Here
Recommended to use a clean jar if you have many mods, if you don't have any, or only a couple basic mods.
You shouldn't need a clean jar.
I am going to test it out, if I have any problem, I will post here.