Two days to the day two years ago, I joined the Minetest IRC asking why my "flat" world started to generate non-flat terrain.
<ROllerozxa> is it intentional that the flat generator only generates a small flat area and then continues with normal non-flat generation?
<ROllerozxa> hm. the world is flat (mg_name = flat), but I had hills turned on. that might be the problem :|
If only I had known about this mod. If you find the "flat" map generator to not be flat enough, don't want random biomes to disturb you, or you feel discouraged when seeing a singlenode void then this mod is definitively for you, giving you a basic superflat world akin to Minecraft's by default. And if you don't like that then you can customise the terrain slices in the superflat.txt file, similar to customising superflats in Minecraft!