Zombie Panic is a HL1 Mod and the Zombie Panic Team has been working on Zombie Panic Source but we tho we could take the media from there site and make the Source for HL1 and still can go to ZP v1.0 Servers and still can play fine without having to download anything.. all we changed was models,sounds,sprites and soon we may take some of the media from the maps they posted and make them for ZP v1.0 ..
Where the screenshots?