This is the successor of NotEnoughResources.
Bleeding edge builds on drone.io
DIY ore graphs
By adding world-gen.json to the JER config folder and toggling the DIY setting ingame you can make your own ore distributions.
You can even use /profile [chunk amount] [all] to create a world-gen-scan.json that will get the distributions from a generated world so you don’t have to guess. These features are quite advanced and only recommend for pack makers or experienced players.