DiIiS Project
Fully-functional open-source server implementation for Diablo 3
...It includes features like dungeon generation, artificial intelligence for enemies, and support for both campaign and adventure modes. The server is designed to be deployable locally or over LAN, enabling cooperative play in controlled environments. While still under active development, it already implements a significant portion of the game’s systems, making it one of the most comprehensive private server projects for Diablo III.