The 1.1 version of brutal Rescue! (Play with Brutal Doom v20)
Zandronum is a free open-source advanced multiplayer sourceport capable of running various games such as Doom, Doom II, Final Doom, Heretic, Hexen, and as well as others online. It originated from Skulltag, which was based on ZDoom and its counterpart, GZDoom.
Zandronum's content is represented by the developers of SpaceDM9 and requires a commercial version of Doom II.
Currently, Zandronum 2.0 can play various modifications created by players up to to ZDoom revision 2.5.0 / GZDoom 1.5.0, older Zandronum only allowed for mods based upto ZDoom revision 1551.