Terragen is a client sided adventure gamemode that generates terrain as you walk to the edge of the generated landscape. Terragen is highly customizable and comes with a several GUIs to help you manage your gamemode. Terragen is also multiplayer, and can support several people exploring the world at once, assuming they are not idiots and fly like crazy into the unexplored ground. That takes a while to get caught up.
There are quite a few easter eggs and two different biomes. Terragen is able to generate rounded landscape and smooth it out based on certain constraints, weighted randomization, and input from surrounding bricks.
