Kingdom of Auspiex Online – http://koarpg.com
quite large 2D pixelart MMORPG . Client has 250mb
freenode / gamedev / kozmonaut (leader)

its a mmorpg, with about 50 to 100 playes on all the time and tons of content like:
– player housing
– crafting
– bard system
– spec system
– multiclass
– badass spells that kill one two or 10 targets
– mini games like crafting, cooking, fishing, lockpicking
– battle system full pvp, allignment based ( you gain more evil allignment killing those with greater )
– if yo evil you can hire gangsters and mercenaries to join you
– even start your own town

development 2005 – 2008, team: 12 core, 1 team leader + main designer, 4 scripters, 1 super prgrammer and artists and a few sound designers