Disney's Toontown Online

Disney's Toontown Online was one of the first kid-oriented MMORPG games. It lasted from 2003 to 2013 until being closed on September 19, 2013 in honor of Club Penguin. Disney's version of the game itself is considered lost, however a user on Reddit has been able to briefly go into part of the server. Many fans are trying very hard to recreate the game. However, the most popular one, Toontown Rewritten, is very laggy, and Toontown Infinite leaked their source code, leading to over 30 other 'private servers' being announced and canned.