Night Terror by NIPPER and Dr.Boo
This is a very old campaign that was never finished.
This whole campaign was one big experiment that I never really got to work how I wanted. It was abandoned after this initial release because of lack of interest in Left 4 Dead. Many things have broken over the years due to various game updates such as static props going invisible on the jungle-themed map.
If you want to check it out it is highly recommended that you play it on a lower difficulty setting.