From the CEO of Bohemia Interactive:
Important notice: effective May 31, 2014, Gamespy will cease providing all hosted services for all games.
This is going to affect multiplayer in our games that use Gamespy for matchmaking, cd keys authentification and NAT traversal from Arma: Resistance to Arma 3. We are planning to introduce an alternative solution using Steam to Arma 2: Operation Arrowhead and Arma 3 users.
Other games (Take On Helicopters, Arma 2, Arma 2: Free, Arma, Arma: Cold War Assault) will have more limited multiplayer experience with loss of server browser, cd key authentification and NAT traversal systems. That said, direct IP connection to servers should work even after Gamespy services are no longer available.
We apologize for any inconvenience.
Gamespy provides server listing services for over 300 games including Halo. While direct IP connections will still work, CD-key authentication and listing features will not. Below is a list of some of the top games Gamespy lists for. While most of them are older, the result of Gamespy shut down will result in a death blow to many legacy PC gamers.
Alien vs Predator (Classic)
Alien vs Predator 2
ARMA
Battlefield 1942
Battlefield 2
Battlefield 2142
Battlefield Vietnam
Battlefield Bad Company 2
Call of Duty
Call of Duty United Offense
Call of Duty 2
Call of Juarez
Call of Juarez Bound in Blood
Civilization III
Commandos 2
Commandos 3
Commandos: Behind Enemy Lines
Commandos: Behind the Call of Duty
Company of Heroes
Company of Heroes Opposing Fronts
Company of Heroes Tales of Valor
Crysis
Crysis Warhead
Crysis Wars
Far Cry
Halo
Hexen
Hexen 2
Jagged Alliance
Jagged Alliance 2
Medal of Honor: Pacific Assault
Medal of Honor: Allied Assault
Medieval Total War
Medieval Total War 2
Multiwinia
Quake 2
Quake 3
Quake 4
Need For Speed: Hot Pursuit
Need For Speed: Hot Pursuit 2
Postal 2
Shogun Total War
Soldier of Fortune
Soldier of Fortune 2
Star Wars Battlefront
Star Wars Battlefront 2
Star Wars Jedi Outcast
Star Wars Jedi Academy
Star Wars Republic Commando
SWAT 2
SWAT 3
SWAT 4
Titan Quest
Tom Clancy's Ghost Recon
Tom Clancy's Ghost Recon Advanced Warfighter
Tom Clancy's Ghost Recon Advanced Warfighter 2
Tom Clancy's HAWX
Tom Clancy's Splinter Cell Chaos Theory
Tom Clancy's Splinter Cell Double Agent
(Starsiege) Tribes
Tribes 2
Tribes Vengeance
Two Worlds
Two Worlds 2
Unreal Gold
Warhammer 40K: Dawn of War
Warhammer 40K: Dark Crusade
Warhammer 40K: Soulstorm
Warhammer 40K: Winter Assault
Unreal Tournament
Unreal 2