Prior to the official SDK coming out am not going to start building maps, it does however make sense to take pre-built maps for other games e.g. team fortress, css and port them into L4D
Now one of the finest games of all-time has some levels that would seem pretty perfect for L4D...
Half Life 2; Ravenholm areas
I've managed to coax this into working but is still very much messy and requires a hell of a lot of texture/model conversion
Pros: prebuilt and wellmade maps
Cons: requires approx 1.35gb of files, some events don't work, zombies don't spawn properly, would breach copyright and server contracts to use
When built, I suspect using this on our servers won't attract too much attention.
I need to get some time (possibly this weekend) when Tess isn't about to put some proper time into it
Will try and post some screenshots this weekend