Anything Realmcrafter don't bother IMO.
There original didn't support any real database engine was flat files and access if I recall was a total waste of my time and money.
If you want a Realmcrafter clone (or rather equal) get ahold of Bards Tale Construction Set, it is stable, has more features and fun. Although single player. They keep jacking up there price and it is still blitz on the back end. I have nothing against blitz mind you, great products.
When it comes to MMO's if anyone is even partially serious and they are an Indy then buying a kit like Realmcrafter is utterly pointless. Get Unity3D
www.unity3d.com or Visual3D.net
http://www.visual3d.net/Home/tabid/36/Default.aspx or even go with TV3D with Rakknet backbone for networking (more coding but doable) finally if you got bucks to spend (quarter of a million dollars or more) HeroEngine
http://www.heroengine.com now that engine kicks ....
Visual3D is a better, friendlier environment, and has a real time editor. Finally you could simply buy Torque, there are a ton of directions to go, Realmcrafter would be the last engine on this planet I would even think about using for writing a game.
Watch the video at this link for a REAL MMO generation engine:
http://www.heroengine.com/world.aspThen think long and hard about time and effort that was put into that thing to get it to be what it is now. I have a friend who works their and have seen there environment, trust me, its a hell of a team they have and one hell of a workload.