Squaresville is a simplified world dominated by abandoned cities. In the same vein as Multi dimensions (though not compatible with it), it occupies a separate "dimension" which actually occurs high in the air (8000 meters, by default). In fact, there are two dimensions -- one with a pristine city, the other with a ruined one (at 10,000). You can teleport to them with the teleport command or create a "key to the city" or "broken key" to take you there and back.
If you want Squaresville to be your main world, set the "singlenode" mod setting on.
The terrain is based on two-dimensional perlin noise for speed and simplicity. There are no caves, but you can use fun_caves when Squaresville is in singlenode mode. City areas are nearly flat -- only the wilderness has any shape at all. All the default biomes are reimplimented in lua, along with most of the stock decorations.
Houses will appear in the suburbs around the city. You can create new houses and save the schematic using the "/saveplot" command.
The source is available on github.
Code: LGPL2, textures: CC-BY-SA and CC0
Mod dependencies: default, beds, doors, flowers, stairs, xpanes, booty?, bucket?, itemframes?, plasmascreen?, homedecor_3d_extras?, inbox?, computer?, lavalamp?, lrfurn?, building_blocks?, chains?, homedecor_i18n?, homedecor?, fake_fire?, moreblocks?, colouredstonebricks?, darkage?
Download: https://github.com/duane-r/squaresville ... master.zip
Note for other developers: This mod does all of the mapgen work in lua, including planting decorations. This allows me to completely ignore chunk boundaries and problems with the C mapgens' decor spilling over into my work. The only random numbers used are for decorations -- all of the terrain and structures are completely repeatable.
Note for fans of the "complete" squaresville: You can still get the original can of worms on github. I no longer maintain it. I've published some of the missing pieces as separate mods.
Fun Tools (chainsaw, flare gun, rope ladders, wall hammer, etc.)
Inspire (rewards similar to the metal/gem crafting requirements)