CCP Games title EVE Online is run on one of the largest clustered super computers on the planet, with 5,000 star systems and several million unique objects in play at any one time. Their server system is so robust that they schedule a one hour down time every day to run backups, and the system can handle up to 25,000 players (and sometimes more) without collapsing.

Because of the gigantic size of the database that players interact with, EVE Online doesn't lend itself to private server play, and there are no EVE Online private servers.

In large part, the lack of EVE Online private servers is a good for the overall play of the game. Much of the appeal of playing EVE Online is the sheer number of players working simultaneously on the universe. Because EVE Online runs on a single cluster, there's never a choice, like in World of Warcraft, or City of Heroes, to decide which server you're going to be on - based on the server your friends are on. You're either on the Tranquility server (if you use the English language interface) or the Serenity server (if you're using the Chinese language interface), and there are usually ten thousand or more players on simultaneously to interact with. There is a third server run by CCP, the test server, called Singularity, and they recommend that everyone set up an account there to test things and provide input into the next development of the game.

By contrast for Worlds of Warcraft, there are dozens, if not hundreds, of private servers out there, that will let anywhere from a hundred to maybe a thousand players log in simultaneously. For WoW, this is an opportunity to "grind in private"; if you tried doing that on EVE Online, you'd have a hard time hooking up with other players at all, due to the massive size of the database to explore.

In a real sense, private servers for MMOs are a dangerous thing for the companies that produce the games. Those games are expensive to write, expensive to maintain, require paid staff to keep on top of things, and require an ongoing development budget and marketing plan. The subscription model you pay is what keeps the game being developed; setting up "hacked" MMO private servers simply hastens the day when the company publishing the MMO can't sustain the operation any longer, and has to shut things down.

Fortunately for CCP, an EVE Online private server is a really difficult thing to set up for a home user; most people don't have home based clusters of high end computers, each with 16 gigs of RAM, to try and make it happen.