Valve have released a beta version of the Left 4 Dead authoring tools, finally letting users make their own levels.
The new tools include an updated version of Hammer, the Source SDK, and example maps and all the props you'll find in the game, as well as a plug-in for Google's SketchUp, a free 3d modelling program that will let users create new props for the game.
The release of the beta comes ahead of a change to the matchmaking system for the game, which will allow the use of the player created content. In their own words "Our plan is to release a beta of the Authoring Tools now so the community can start working on maps in the full environment. In a few weeks we will then release the updated match making to allow users to play those new maps and campaigns."
If you want to grab the tools, head to the 'Tools' tab in your Steam browser and download it, but remember that you have to opt-in to betas. (The option is in your Steam settings)
I'm steeling myself for a wave of levels based on body parts, and the inevitable Zombie Balls campaign is going to be singularly grisly, but I'm thrilled that I can now make the Left 4 Dead level I always wanted. Bad Apple: Assault on the Rainbow Orchards.