A while ago I discovered Minecraft4k, a java demo written by Notch fitting into a 4kb object file. He used software raycasting to rasterize a large 3d array of voxels. The original demo can be played here as an applet:
Again, I have produced a small demo of the Tengu Engine as my own way of experimenting with what may be possible as it progresses along its development path. While work is already under way on the hardware renderer, it still has not been integrated into the main code so this demo here still uses SDL for all of the rendering. What it shows is a top down perspective using a destroyed space ship tile set I made recently. There are ray traced shadows as well as what I refer to as gradients, or distance based mask pattern selection, to give the illusion of light or visibility falloff, which is a technique somewhat similar to dithering I suppose.