SLASH

SLASH is a variant of NetHack 3.1.3, later updated to NetHack 3.2.2. It initially combined NetHack-- 3.1.3 with NetHack Plus. The subsequent addition of the Wizard Patch produced SLASH'EM.

NetHack 3.3.0 accepted the Wizard Patch into the mainline code, and consequently SLASH ceased to exist as a separate game from SLASH'EM.

Source code
SLASH at the Wayback Machine