Sky Island Producer

A world type that generates the overworld as one giant floating island in the void - plus one command that packs the whole world into a zip you can hand to anyone.

• Sky Island world type. The overworld is pure void except a single island at (0, 0): radius 200 blocks, based at y = 80, about 48 blocks thick. Nether and End stay vanilla.
• Nothing about it is fixed. The island's shape comes from the world seed, and each world draws 5 random biomes from a 22-biome land pool and spreads them into contiguous regions. The surface follows the biome.
• A playable survival island. Stone under a biome surface, no cave carving (the island is solid rock), and normal biome decoration, so the biome's trees, plants and ore veins are there.
• /skyisland export [radius] pre-generates the island at 4 chunks per tick with live progress (no server freeze) and zips the entire save folder to skyisland_exports/<world name>-<timestamp>.zip. The zip's top folder is the world name, so it unzips straight into saves/. A 64-block radius island is about 880 KB.
• Servers: add -Dskyisland.autoExportRadius=200 to export automatically once the server has started.
• Tunable without touching code: radius (16-1024), base_y, thickness, biome_count and the biome pool, in the world preset JSON or overridden by a datapack.

/skyisland spawn        # teleport to the island centre
/skyisland export [r]   # pre-generate + zip the save (default 200, 16-1024)

Versions: 1.20.1 Forge 47+ | 1.21.1 NeoForge 21.1+. Install on client and server - the world type is picked in the world creation screen.

Commands need permission level 2 (cheats in single-player, OP on a server). Vanilla structures such as villages and ruins still try to place on the island; override the structure step with a datapack for a bare island. Licence: MIT.