List of WoW: Cataclysm server emulators (Cores)

For 4.0.6а:

• SkyFireEMU
• ArkCORE
• ArkCORE2
• Darkcore

For 4.2.0:

• SkyFireEMU_420

For 4.3.4:

• MaNGOS
• TrinityCore_4.3.4

For  5.x.x
-- none releasable yet, several dev. teams work on creating a properly working core (system)