L4D2 VR Prototype

Things that work

Download L4D2VR.zip and extract the files to your Left 4 Dead 2 directory (steamapps\common\Left 4 Dead 2)
Launch SteamVR, then launch Left 4 Dead 2 with these launch options:

-insecure -window -novid +mat_motion_blur_percent_of_screen_max 0 +crosshair 0 -w 1280 -h 720 +mat_queue_mode 0 +mat_vsync 0 +mat_antialias 0 +mat_grain_scale_override 0
At the menu, feel free to change these video settings.
Load into a campaign.
To recenter the camera height, press down on the left stick. To see the HUD, aim the controller up or down.

The host must have the mod installed and the server must be set to local. Other players can play in VR too (if they also installed the mod).
To host a local server, click Play Campaign -> Play With Friends -> Create new campaign lobby -> Server Type: Local Server
You can make your game public if you want.
Versus works but it's barely been tested.

If the game isn't loading in VR:

If the game is stuttering, try:

Steam Settings -> Shader Pre-Caching -> Allow background processing of Vulkan shaders

If the game is crashing, try:

Note: After building, it will attempt to copy the new d3d9.dll to your L4D2 directory.