I've always wanted to play in a floating islands Minecraft world, but when the official floating islands generation was released it was disappointing for multiple reasons, which I have aimed to improve with this data pack.

Features

Floating islands with multiple biomes
Custom biome generation that only includes appropriate biomes
Floating island surfaces at different elevations
Ores spawn regardless of altitude
Islands have vertical features on the surface
No massive landmasses

Screenshots

Taiga wide

Tele

View up

VIllage

Sunset

Installation

1. When creating a new world, load and enable sanonasu's floating islands data pack by clicking on Data Packs, dragging and dropping the .zip file onto the Minecraft window and moving the data pack over to the Selected column.

2. Adjust any world options you want EXCEPT World Type under More World Options. Leave it set to Default.

2a. Due to the way Minecraft generates structures, they sometimes load incorrectly in a floating island world (at y: 0 hanging over the void). I'd encourage you to consider turning off structures if this is something that bothers you.

3. Create New World and enjoy!

3a. Some spawn locations might be particularly nasty. If you're unhappy, I'd encourage you to try a different seed.

Compatibility
sanonasu's floating islands IS NOT compatible with any data pack that edits the world generation of the overworld dimension. This includes editing biome generation or adding new biomes to the overworld.

sanonasu's floating islands IS compatible with any data pack that edits the world generation of the nether or the end, or adds custom dimensions.

Known Issues

- The terrain and biome seed isn't randomised each time a world is generated, meaning that every world generated with a random seed will be the same. Currently there is no way to fix this due to the feature still being developed by Mojang. I'm not aware of any workaround available to this issue for now.

- Structures generating at the bottom of the world when there are no blocks from y-0 to y-256. (possible fix by THINK86200)

Offshoots

dburgdorf's Rainbeau's Sky Islands

GurkenatorHD's Fancy Floating Islands

Better Floating Islands