Today Valve are moving the Left 4 Dead 2 Workshop out of beta. So, right now with a click of a button, you can add campaigns, items, clothing, weapons and more.
Content creators have been hard at work creating content for L4D2 but they have just gotten access to the new Workshop, so give them some time to upload their work. But with over 1,000 community campaigns and thousands more items and skins already created for the game, we should see many of these pop up in the Left 4 Dead 2 Workshop in the coming days and weeks. Valve also don't want you to upload other people’s work. If a campaign you like isn’t in the Workshop, please nicely ask the creator to post it. Valve explained how to upload files, for those of you in need of help:
To add content to L4D2: Load up Left 4 Dead 2 (or browse to it here). In game, click on the add-ons section from the main menu. There you can see add-ons once they are downloaded or choose browse the Workshop. Go into the Workshop, find a something you like – let’s say a skin for Francis where he is in a cop outfit. Click the subscribe button and it will automatically download and appear in the list. If you are doing this through the web browser, it will appear next time you start the game.
Please note – the Workshop has increased its file size limit to 200MB. But this still means some of the larger campaigns will be broken up into sub-200mb chunks. Those campaigns will be in collections and you will need to subscribe to the collection to get all the files.
This is just one more thing on the long list of reasons why Valve are in charge of this industry. The freedom they offer you is like no other.