Hi cyberblade,
sorry for delay but due to spammers I have to do moderation for the first post of each user.
Now, Runescape is not built with DimensioneX, it's built with Flash. Therefore making something similar (or even better) will be very very hard.
For a hint of what you can achieve with DimensioneX take a look at Underworld Online,
http://www.underworld-game.netOn the counterpart it's relatively easy to learn and we ask nothing, neither to play nor to host games on our servers.