NOVA (Neatly Organized Voxel API) is a modding framework for voxel games.
It provides an abstraction that is easy to use and maintain while giving developers confidence that their work can be used across different voxel games and their versions.
NOVA consists of two parts, NovaCore and and the NOVA game wrappers. If you are a game user you probably want to get wrapper for your game.
If you are a mod developer you may want the mod template. You can get it here as a zip.
See NOVA Gradle and Getting Started on Nova Docs