Minecraft, the insanely popular and incredibly deep indie gem is not an MMORPG, but allowing over a couple thousand players to play on one server makes it a close call. The sandbox D.I.Y. nature of the game allows players to do pretty much anything in the game, expanding it with mods, but some are using it to do some really positive things.
Massively Minecraft is a community of Minecraft players that, as their website states:
?Massively Minecraft is a Guild based learning community for kids aged 4-16 who are interested in developing digital media skills, exploring their creativity and developing online social skills using the video game Minecraft. Our guild is a social-enterprise, founded in mid 2011 for parents, teachers, schools and researchers as players in an open world to learn together, using game-theory and our experience of developing process networks in virtual worlds.?
This is really cool to help kids get more familiar with the internet in general, the way an internet community works, and how to play a fun game while being in an environment that is perfectly safe for them that parents can trust. More games, such as many MMORPG games should have guilds like this to help the younger kids get into gaming early.