It's called Resident Evil: Cold Blood, and is pretty much the definitive mod for Res Evil
It's very similar to outbreak, in that you pick from 8 different characters, all with different proficiencies and weapons
Now since most of you seem un-inspired from these mods, I thought I would post some Screen Shots to prove to you how awesome this is;
Crawling Zombie - Standard First Person View

Iron Sights View against Zombies

Third Person (RE4 Style) View against Zombie, guns without Ironsights target better in this view

The flashlight in 3rd Person

A dead Zombie, notice the trademark RE pool of blood which confirms a zombie is dead (or is it, Crimson Heads...)

The Mega Awesome Flashlight in 1st person

Green and Blue herbs

How to use healing items via the command console

As I said, AWESOME
If you want to play, you will need the latest version of STEAM, a UNIQUE registration/cd key of half-life 1, and to download the latest mod version in the above link
If you are a vista user, you can follow steps to get this playable via the news section, and an article on Vista Patching