Sven Co-op

Sven Co-op (usually abbreviated as SC) is a multiplayer modification for Half-Life. It is still under active development and is currently at version 4.5. It is one of the oldest Half-Life mods to be still in development.

This mod is a cooperative game, where players must work together against AI-controlled enemies NPCs and solve puzzles as a team. The majority of the maps are user-created with the exception of the original maps created by the Sven Co-op developers. Some of the most popular maps are 'Crystal', 'The Escape Series' and 'Osprey'.

Old Weapons

 * Half-Life Crowbar - If the user is a donator, secondary fire makes it much more powerful against hostile NPCs, but drains suit power. Now has a tertiary fire where the crowbar is thrown.
 * Pipe Wrench - Same as the Opposing Force Pipe Wrench, only now it can repair and revive turret NPCs.
 * Barnacle Grapple - Can either pull the user to an NPC, player or special texture, or can be used to rappel from large heights.
 * 9mm Pistol - Identical to the Half-Life 9mm pistol. Secondary fire shoots faster, but less accurately.
 * .357 Magnum - Identical to the Half-Life .357 Magnum, with the Half-Life Deathmatch zoom for a secondary fire.
 * Desert Eagle - Identical to the Opposing Force Desert Eagle.
 * SPAS-12 Shotgun - Instead of firing 2 shells at once, secondary fire now shoots in automatic, being extremely powerful but inaccurate.
 * Crossbow - Identical to the Half-Life crossbow, except now bolts fired without zooming in explode on impact.
 * RPG - Identical to the Half-Life RPG.
 * Gauss Gun/Tau Cannon - The Secondary fire's recoil may or may not be highly exaggerated as in Half Life Deathmatch; Whether or not is up to the mapper.
 * Gluon Gun - Identical to the Half-Life Gluon Gun.
 * Hivehand - Identical to the Half-Life Hivehand.
 * Frag Grenades - Secondary Fire now throws all of them in one projectile, called a "banana bomb".
 * Satchel Charges - Can now be picked up or kicked once thrown.
 * Tripmine - Identical to the Half-Life Tripmine.
 * Snark - For donators, Secondary fire now releases a chumtoad that hinders enemy ranged attacks and also poisons NPCs. This only works if the player has at least 10 snarks.
 * M40A1 Sniper Rifle - Same as the Opposing Force sniper rifle, with increased damage done, and less accurate without the scope.
 * 5.56mm M249 SAW - Identical to the Opposing Force M249 SAW.

New Weapons

 * Medkit - Allows you to heal other players by 10 points and revive non-gibbed ones for 50, although a player can only carry a max of 100; the points regenerate over time.
 * 9mm Uzi - 32 round submachine gun. Can be held in akimbo for more power and a longer reload time. Donators can use Golden Uzis, which do considerably more damage.
 * 9mm MP5 Submachine gun - Fires in Full Automatic, secondary fire zooms in.
 * 5.56mm M16 w/ m203 grenade launcher - Fires in a 3 round burst. Grenades now have to be individually prepared before firing.
 * 5.56mm Minigun - Unlike other weapons, must be picked up off the ground using E, and must be dropped before using another weapon. Fires in full-auto, with a long revving up time. Uses a single 600 round clip, additional ammo is added to the clip through SCXPM Ammo regeneration, picking up other miniguns, etc.

Gameplay
Sven co-op (as it's name suggests) is a game that relies on cooperative effort. Examples of this are: a player crouching so the other player can use them as a boost to go into a vent to open a locked door from the other side so they can both continue, making the players work as a team to defeat a enemy or "bosses" (usually used as term to refer to a final enemy/enemies that are tougher or the toughest of the normal enemies), healing teammates to prevent their deaths and even reviving a teammate when they have fallen in battle. The actual battles are full of action, and the hostiles range from human grunts, to Xen creatures (headcrabs, vortigaunts,alien grunts, etc.) and race X (pit drones, shock troopers, and voltigores).

Maps
Although some maps are included with sven co-op, a majority are made by the community. Maps come in quite literally, all shapes and sizes. Some maps are very long or in a series (e.g. The escape series where the players are "used as lab rats", and decide to escape) or very short (e.g. sc_subway train where you and the team of players gets to the osprey helicopter). The gameplay ranges from standard walkthrough maps, where you fight your way from point A to point B for little or no reason, to maps where several players fool around in an amusement park-like area. there are also tower defense maps, where players must survive an onslaught of enemies, and even "Maze" maps where players must navigate through huge, complicated mazes in first person.

Sequel
Sven Co-op 2, using the Source engine, was in development. and is currently on hold until they have finished the first mod.Latter it has been confirmed multiple times, that its highly unlikely that Svencoop 2 will ever return to a development stage.