Skirmish 4 is a megawad with over 99 maps for Deathmatch. It also includes Dwango, Greenwar and other DM maps. You can also play this in Singleplayer for weapon testing, monster testing, etc.
A megawad with 99 maps made for Zandronum Deathmatch.
Skirmish 4 is a wad with over 99 maps that restores Dwango, Greenwar and other levels. Also playable on GZDoom for weapon testing, monster testing, etc.
Fun fact: If you warp into Map 40, you can hear a MIDI version of Smells Like Teen Spirit by Nirvana. (I'm a fan of Nirvana)