"Since the Left 4 Dead Authoring Tools Beta was released several weeks ago, mod authors have been cooking with gas, so to speak. The ranks of dedicated community members working hard to create new content have been swelling, and a very hungry horde awaits," Valve's Yasser Malaika wrote on the Left 4 Dead blog. "We've long believed that Left 4 Dead should fully support community content, and we've been hard at work enhancing the UI and matchmaking systems to provide full support for your creations. The latest update, which will be available via Steam next week, is focused on custom campaigns."
Included in the new features introduced in the update is support for Add-Ons, which will let authors pack maps, posters, models and textures into a single file which players can download and then install by either double-clicking it or dropping it into the new "addons" folder. Matchmaking has also been updated to support searches for games based on installed add-on campaigns. The improved system will simplify lobby creation and allow gamers to invite friends to custom campaigns; if the invited player doesn't have the required add-on installed, an option to automatically download it will be offered.
The update will also mark the end of the open beta and the official release of the Left 4 Dead authoring tools/SDK. The final release will come with "a few fixes and several new additions," including an expansion of the tutorial and the source files for all the official campaign maps. Detailed information about the new updates will be available at Valve's Developer Community Wiki.