Hello there ^ctesjbuvf
Unfortunately, it is not allowed to talk about third party modifications of any game, and the only way of running two or more copies of d2 is that way, which is against Blizzard ToS and also d2jsp rules.
Quote
12. No binaries, hacks, bots, exploits, or third party modifications of any game or program.
Taken from:
https://forums.d2jsp.org/info.php?p=9Have a good day!