This mod needs to be cleaned up to meet the standards of the Mod Template.
Lambda is a campaign by [X6] Herbius which aims to bring the best of Half-Life 2 to Left 4 Dead. The campaign currently features nine maps, ranging from the City 17 station, alongside the railway and ending up at the old canals.
The latest version of the campaign, Delta 1.2, can be found here: http://lambda-l4d.webs.com/downloads.htm. Note that since the campaign uses content from Half-Life 2, you will need to own the game and the content will, at present, need to be extracted manually. See http://lambda-l4d.webs.com/contentextractionguide.htm.
An early alpha trailer of the campaign can be found here: http://www.youtube.com/watch?v=wm6dhQrvmkc.
The current poster for the Lambda campaign. See http://lambda-l4d.webs.com/ for more information.