this is a browser-based MMORPG (massive multiplayer online role-playing game) but its a full 3D world. you don't have to install anything, you just have to have all the latest Flash plugins. it's like a super simplified version of the usual 3rd person medieval skill-based RPG, melee weapons, armor, amulets, monsters etc. its really simple, even the quests and all, which makes it surprisingly addicting! i even ended up putting up my own clan ^_^ anyway, try it for yourself.

The Esoteric Order of the Dragon
bwahahaha, here's the homepage of the clan i made in Sherwood Dungeon
if you guys get bored, join in and ill put you in the council ^_^