This is something I've been saying for years. Why is everybody so damned dependent on the EQ client? After three decades of the genre existing, is there not one single option out there that people can use to build their game on that isn't someone else's private code? Seriously, are there no open source or open license MMORPG engines available after all these years?
If so, then why doesn't someone write one already. Clearly there is a need after all of these years of EMUs (not just EQ, but WoW and the rest.... there's been tons of MMORPG EMUs). There's clearly a market for it.