TheArchive.Essentials

That one massive GTFO Quality of Life mod.
All Features are toggleable in-game, and most of them mid-game.

Highlighted Features

Loud Volume Override

Lower or mute the game during the intro sequence and while dropping down with the elevator.
Also allows you to adjust what happens with audio whenever you tab outside the game:

• Continue playing
• Lower Volume
• Mute

Player Lobby Management

Open up players Steam profile or, if you're the host, kick them out of your lobby.

Carry Item Marker

Big pickups (like CELLs or FOG_TURBINEs) get their own color as well as the item name above it.
Also shows a marker on whoever is carrying a big pickup.

Glass Liquid System Override

Change the resolution of the system that renders the blood splatters and other liquids on your visor or disable it entirely.
Disabling the system entirely prevents/"fixes" the so-called "Void Bug" from happening, where sometimes a blob of darkness, the big black blob consumes your entire screen, making you unable to see anything for a few seconds up to minutes at a time.

Sentry Markers

Adds a player colored marker on placed down sentry guns, with who placed it and the sentries type above it.

Show Weapon Stats

Displays the weapons stats on the weapon select screen.
Damage, clip size, max ammo and more

Glowsticks!

Change the base color to any of the available ones (Green, Yellow, Orange or Red) which syncs to other players!
And/Or override the color locally (for yourself only) based on one fixed color or based on who threw the glowstick.

Loading Indicator

Displays a little indicator that shows if other players have finished loading yet.

Nickname

Change your name in game, includes a color option.

Player Color Override

Allows you to change the colors of you and your teammates.
Additionally allows you to colorize other players based on their nickname color.

99% Reload Fix

Fixes the bug that leaves you with one bullet short in the mag even though enough ammo is available.

L4D Style Resource Packs

Use left and right mouse buttons to apply resource packs instead of E
Left mouse = yourself
Right mouse = other players (can be held down + hovered over a player to start the interaction)

Disable Hud Sway

Makes the in-game hud stay in place while running, jumping and looking around.

Disable UI Mirroring

Removes the mirroring effect on UI elements.

Disable UI Parallax

Stops the movement of UI elements in menu screens (Loadout, Rundown, ...) whenever you move your cursor around.
(Some elements might get partially or fully cut off-screen!)

No Dead Pings

Fixes pings (red triangles, doritos) staying on dead enemies as a result of high ping.

Remove Story Dialog

Prevents all level-based voice events that have subtitles assigned from playing.
(Goodbye Schaefer & Co 😥)

Skip Elevator Animation

Automatically skips the cutscene after initiating a cage drop.
This leads to faster load times as the game only starts building the level once the cutscene is over.

Bot Customization

Customize your Bots appearance as host and change their names. (Syncs to other players!)

Process Priority

Automatically change the games process priority, potentially increasing performance by a tiny bit.

Other things not mentioned here

Check the List of all Features for everything else.