It might still not be out of Early Access, but Killing Floor 2 finally has Steam Workshop support.
If you're up for more hot Zed action, have a peruse of our list of PC's best zombie games.
Tripwire Interactive have released a new patch for Killing Floor 2 that adds Steam Workshop, so you can now install community built mods by simply ticking a box. The future is brilliant.
Admins can even apply a selection of mods to specific servers, creating lists so players who want to join can go and easily tick them off and jump in. If you're an admin and you want to learn how to set that up, Tripwire Interactive explain how here.
There are already a bunch of mods on there, from a selection of varied community-created maps to changing the names of the guns to their real world counterparts to, erm, making the Bloat Zed variant pink. Head over to the Killing Floor 2's Steam Workshop page and take a look for yourself.