It wasn't a private server. It was the entire july 2008 game client legally reverse engineered, and ported to the lithtech engine with bug fixes and...
It's kind of ridiculous for fools who host these private servers to not make it open-source. For a community as small as Combat Arms, hosting private...
Also, for full transparency, anything that I find useful to hacking MapleStory would be published as I want to promote learning the approach to game...