I'm sure many of you have seen Runescape (http://www.runescape.com) by now.  All I can say is WOW!  When I started the game, by jaw dropped.  I couldn't believe a 3D/iso Java applet MMORPG running like that.

Now of course I wanted to take a look at how it works, but there's no info on the web.  For those who are going to decompile it, don't bother, it is obfusticated.  It is a large game, so reverse-engineering all that obfusticated code would take a long time.  Additionally, the company that made it, Jagex, lives off this software and their engine technology, so it wouldn't be a nice thing to do.  So if you guys would like to speculate about how the game works, I'd be very interested.

It seems the world is based on a kind of heightmap, in which each square has a height and a color.  Then houses and objects are put on top of that.  Characters are not full 3D, as the graphics switch only when you rotate ~45°, as they did in old raycasting games (Wolfenstein, Doom).  Most objects (fires, mushrooms, etc.) are only flat shaded (ie. no textures).  However, houses are texture mapped.  Some GUI components are alpha blended.

I'd say their doing a lot of rendering every frame, unless they've found a really clever way to optimize things and avoid redrawing the majority of a frame.

from, Stefan