ZenXArch's Skyblock

The mod adds a Skyblock world preset and a Flatblock preset, both reached from the create world menu. The Skyblock preset produces an empty void with a spawn platform at y=0, and biomes and structures still generate, so a player can grow an island from one block placed by hand or by generated features. Chunk regeneration exploits do not work in this setup. Installation requires Fabric API, and the mod is available for Fabric and Quilt across nine release versions, 1.21.1 – 1.21.11.

The mod aims for minimal change to vanilla Minecraft. Stronghold portal rooms do not spawn, the Ender dragon and the exit portal do not appear by default, and the starting portal still does. Players respawn the dragon themselves. Getting lava needs the lava gamerule turned on. Each world can carry an expanded skyblock challenge, and the author describes the Ender fountain steps in a separate guide, where end crystals are placed at the fountain coordinates taken from a vanilla world with the same seed. Server owners should note that players trapped in hardcore worlds can go through the portal.

The mod runs on the server, and players can join with it unused, since the client side is optional. It is open source under the Mozilla Public License 2.0, and public links exist for the source code, the issue tracker and a wiki. Snapshot builds are published alongside the release files.