__Main contributors__

Brad Myers: mexican NPC and horse models/skins
Dieko: view model fists and skin, vigilante and desperado player models
Flakk: most view model animations, gatling skin
Jeremy Dulary: 2d Art, animations/rigs: knife, snake, horse; models: tree, snake and hats
Psychonic: Linux build, misc. code and support
Racer445: Peacemaker skin/animations, Henry rifle skin, Deringer skin, Winchester shotgun model/skin
Sonic Valley Team (sound design/music): Stringed_evil (lead), Havokmann, PhreaK and Dimitris Plagiannis

__Occasional Contributors__

Angel Eyes: sound design for v3.5, custom sounds pack: detpak.tripod.com
Anime7Angel: train engine, coal car and Wells&Fargo stagecoach
Cat: weapon animations (Sharps, dynamite, Deringer)
Dave: web hosting
Enron: coachgun skin
Fenix: Revenge map
Freak: additional level design for Tijuana and Desperados maps
Gary Welsh: player model concepts
hhh316: world textures
Hessi: Sharps rifle model/skin
Jackennils: Desperados map (CS:S version)
Joe Jack Wagner: les absents -version instrumentale- (menu background music)
Kaskad: Colt SAA Peacemaker model
Kelvin Tam: Sawed off double barrel shotgun model/skin
Masher: Axe and Henry rifle models
Michael 'nifty koala' Phillips: player taunts
Owen Lawrence: cactus logo
Leon Kilean: Loothill map, misc. textures, Walker and Smith skins
Macaroane: coachgun and Deringer models
Martidore: Colt Walker model
Millenia3d: Mare's Leg skin
Morricone: Robertlee map, support and feedback
Prodigy: some re-skins (dynamite, players)
Steve Mazzaro: old menu music, round end anthems for normal modes
Thomas (wickit) Beglin: sawed shotgun animations, brass knuckles integration
Rasmus: S&W Schofield model/skin
Smiechu: Brawl map, support and feedback
Tigger: Smith carbine, Mare's Leg model, some props
Wesley Tack: Chuck wagon prop
Yester: Railhouse and Abandoned maps, support and feedback

__Translations__

Yester (French), pedro0930(Chinese), LizardKing(Italian), Kissamies(Finnish), Denis Skurat "Dionys" (Russian), MadMakz (German)

__Playtesting__

Arkanol, arklansman, Benn, BloodyPotato, Cherokee Bill, Daffy_Duck, freedomorfire, Gothic, Gordon-Shepherd, javert, Kenton, muted, OkeiDo, Pickajoe, poudjik, RampantAndroid, silverfox, Simon, The Buttery Lobster, Tom, twentyTWO, youstolemykill, ze AVAIR, Lorderex, Suntio, Smiechu, Yester, Wickit, Fl4x0n, Petzi, Dave, I am Wiesel, IceCube, Dr Snowie, mook, bugme, Poseidon, AWhDRi, CoHach, Als, MangoJuice, LRyder2k6, Bublgum, treeturtle

__Misc__

Assets from CG Textures and Freesound.org
Battlegrounds2 mod: weapon smoke code and mod options panel
CURL and SQLite libraries
Jonathan White : outline glow effect
Saul Rennison (CSPromod): Dynamic RTT shadow angles code and self body awareness code hints
Tom Edwards: libcurl implementation in Source

R_Yell and the whole FoF community for the rest.