More zombie madness is coming our way, as Valve announced that it will release a new update for Left 4 Dead sometime next week.

The update will focus on custom campaigns, providing mod authors with non-beta mod tools. It will now include source files for all of Valve’s campaign maps, as well as an example campaign add-on tutorial map.

It will also allow content creators to use a new framework that will package their content into a single “VPK” file which can be installed by just double clicking on them, or dropping them into the game’s new ‘addons’ folder.

Finally, the update will redo the game’s matchmaking system, adding support for custom campaigns and making it easier to create a lobby.