Is there a world generator that can create a Minecraft world that is solid rock?

Solution 1:

Quite the contrary, it seems really easy to do with MCEdit (I've just tried it).

• Start MCEdit, create a new world. Put in a few numbers - how large a world do you want to have?
• Once the world is generated, press ctrl + a. That selects the whole world.
• Select the Fill tool. Pick stone and pres fill.
• Similarly, fill the bottommost layer with bedrock. (set the selection height to 1.
• Take care to place the spawn point wherever you like it.

Save, and you're ready to go.

Solution 2:

World generation now comes with a powerful preset tool. The code for generating one layer of bedrock followed by 127 layers of stone is:

2;7,127x1;1

Solution 3:

You can download a flat stone world. Just extract to the same location as your other worlds.