Multiple Game Instances - bolrog/d2dx GitHub Wiki
For so called "multiboxing", or allowing multiple instances of the game at the same time, try this open source project:
https://github.com/mir-diablo-ii-tools/SlashGaming-Diablo-II-Free-Multibox
For so called "multiboxing", or allowing multiple instances of the game at the same time, try this open source project:
https://github.com/mir-diablo-ii-tools/SlashGaming-Diablo-II-Free-Multibox