Possibly to avoid conflicts with Nethack4[0], which was a fork of the Nethack 3.x series back when development was stalled. I think the guy behind it later join

Possibly to avoid conflicts with Nethack4[0], which was a fork of the Nethack 3.x series back when development was stalled. I think the guy behind it later joined the main Nethack dev team. [0] http://nethack4.org/ http://nethack4.org/