With Red Eclipse being released soon, I thought I'd bring up the topic of servers with custom map rotations. I believe this feature could help with the idea of a Quadropolis map server that was discussed for Sauerbraten a few months ago.
The Red Eclipse servers can load their own maps from "data\maps\" and can have a custom map rotation list. All one would need to do to create a Quadropolis-only map server would be to extract the maps into this directory, and edit their servexec.cfg. Below are the vars that I believe would need to be changed.
sv_campaignmaps "" // campaign maps
sv_allowmaps "" // allowed maps
sv_duelmaps "" // duel maps
sv_mainmaps "" // deathmatch maps
sv_ctfmaps "" // ctf maps
sv_mctfmaps "" // multi-ctf maps
sv_stfmaps "" // stf maps
sv_trialmaps "" // time-trial maps
sv_maprotate 2 // server side map rotation of above maps; 0 = off, 1 = sequence, 2 = random
On a side note, one may want to set sv_mapslock 5 to disable all map selection and let the server choose.