Hello,
DSI once was an official map, which got kicked out due to the source gone missing and other problems. Personally I think it's not bad at all but needs some attention.
With div0's patches to q3map2 it is possible to decompile .bsp files and often get *good enough* .map files. I decompiled DSI, fixed problems triggering q3map2 compile problems and uploaded the reconstructed sources: http://savagex.planetnexuiz.de/dsi_converted.zip
If somebody feels like giving it some love (it's mostly fine now) go ahead and toy around with it (if GTKRadiant cannot open the .map file you need to check "Preferences" -> "Brush" -> "Use alternative texture-projection"). The lighting is mostly flat (notice the minlight setting in worldspawn) and it would be a good start for tweaking.
Just posting this in case somebody has sweet memories on this map.