This collection contains every "L4D2 Research & Developpement" Mod that I and other modders released on the L4D2 Workshop.
A "R&D" mod is a mod that contains "never (or almost never) seen before" mechanics. If you want to see "unique" Mods (at least when they came out), you're at the right place.

Below, you can find a little description for each mod, about what novelty it brought to L4D2 :
For a technology that has numerous examples, the most descriptive one is shown. At an equal level, the most popular is shown :

195 HD Molotovs [Pure RNG]

• This mod is the first one that uses a "Pure RNG" witch allows the first person skin to match the third person skin "picked", even though there are multiple different skins in the same map. The skins sometimes does not match however (but changes), when a Molotov is picked among a group of other Molotovs.

Alma Wade (F.E.A.R x L4D2)

• This mod adds "Alma Wade", the little girl from F.E.A.R into the game. It makes her appear randomly at some places in the world. Besides that, it also contains a sort of "cutscene" that consists in the timed spawn of different materials. This mod was the first to introcude the "cutscene" concept and was also the first one to feature "random scary elements" that appear in the world

Clean Zoey Legs

• This mod showcases a new and way more efficient and powerful way to "Mod a Mod". Basically, modding a preexisting mod (at least its textures : VMT and VTF) is made by just adding $cdmaterials lines that will be used in priority over the others, to set new skins. This opens the road to "A la carte" survivors with options to trigger different pieces of clothing and selecting their textures (with RNG too) individually.

Energy Drink Adrenaline & Vending Machines

• These 2 mods are the first that use the "Synergy" stuff. Basically, the texture of the Adrenaline matches the texture of another object in map. This is simply done by adding the adrenaline materials in the vending machine and vice-verca, then using a proper RNG (Linear Ramp or Entity Random) to link them.
  This mod however only showcase very little potential because both objects are just synced. It's possible otherwise to use certain objects as triggers for other ones (like Pure RNG does).

HD Machine Guns (+HUD Display)

• This mod showcases that it's possible to link an in-game object to the HUD by including a "trigger texture" inside the model that will be reproduced on the HUD.

HD Pan

• This mod showcases the use of "Melee DMG" (MDMG) technology, that allows the melee weapon to really get damaged after a few hits. The model itself changes depending on a certain number of hits. The code can't, however, count after 5 hits.

HD RNG Stuffed Animals

• This mod showcases the use of "Prox RNG" technology, witch is a way to include Real RNG (different textures / objects within the same map) for certain map objects. Basically, it changes the texture/shape of the object when the player goes far enough from the object.

Hunter & Huntress RNG Mod

• This mod is an installement of "Model RNG" on an object with a skeleton. It includes a "fix" for the ragdoll issue (the dead bodies match the last infected alive). That "fix" can also be applied to survivors. Other mods like this exist, like Zetnus Male/Female Witch.

iPhone 6 with WhatsApp for Pills

• This mod was a sort of personnal challenge to try and implement a lot of different features altogether. It's the first mod that can be "player controlled" on any server (since you can stop to open WhatsApp if you have any message). It's also the first mod to use more than 100 different proxies. It also contains the (very likely) most complex single VMT that there ever was and will ever be.

Rickenbacker 4001 : Color RNG

• This mod is one of the first installements of "Color RNG", a kind of RNG that randomizes the color of a certain item and can give it any color among the 16'387'064 avaliable. Yet no "Real RNG" is avaliable, it's only per map. Plans for a new version (per item) in the future have yet failed. Pure RNG is therefore not really possible (technically yes, but the game doesn't like that).

Synthetic Zoey

• First mod for L4D2 to use an Emmisive Blend Texture ($emissiveBlendTexture) to create a multidirectional flowing texture on a model. Also features proxies coding on eyes.

The Ring TV

• This mod features heavy programming with proxies (more than 50 proxies in a single VMT to write a code). It uses the direction the playing is facing and the distance between the TV and the Player to modify the animation accordingly (animation "loops") and create a new "realistic" effect : you have to go close to the TV to trigger the girl and make her go out of the well.

Realistic Damage

• This mod is the Core mod of a whole new technique that allows realistic damage (blood, boomer and fire damage) to be applied to survivors, using the Health proxy. Packed with a lot of coding to remove any glitch that could occurs, this is the biggest programming mod ever released on the L4D2 Workshop so far. Containing VMT with more than 100 proxies and 120 variables, it's truly and actually a small software coded inside the textures themselves.