Duke Nukem 3D: Megaton Edition has been patched with addition of eight-player co-op throughout the entire game and all official expansions.
Player Attack reports the update is now live on Steam, and also adds three new achievements.
The new co-op features allows you to play with up to seven others across any single-player map, or any of over 200 community maps given the go ahead to support the feature.
There is no distinction between player-controlled characters, which sounds exactly like the kind of rampant chaos publisher Devolver Digital likes best.
Duke Nukem 3D: Megaton Edition is currently on sale on Steam.