Ribbon World

The mod removes the terrain limit along the plus and minus Z direction, so generated land stops at a fixed rectangular border instead of extending indefinitely. The overworld spans 384 blocks, which is 24 chunks wide, and keeps the usual build height from -64 to 320. The nether and the end span 256 blocks, 16 chunks wide, and keep the build height from 0 to 256.

A one-chunk wide barrier of wall blocks marks the edge between generated terrain and the void. Nether portals are kept from generating outside the border in the overworld, and end gateways are kept from generating outside it as well, with the Z coordinate of the gateways set to 0. Non-player entities outside the border are removed, so shulkers do not remain floating in the end beyond the edge. The mod also tries to keep players from spawning outside the border, though a spawn may still fail if the game cannot find a valid position, and an ocean spawn inside the border is the usual result.

Ribbon World is open source under the CC0 1.0 Universal license and needs Fabric API. It runs on the server alone, so players join without installing anything. Files are published for Fabric only, for game versions 26.1.2 and 26.2, with 1.1.4 for 26.2 as the latest file.