Randungeon
Phii

adds highly randomized vivid dungeons to the world, and tools to spawn/customize them.

Too Many Stones
JoeEnderman

35 new stone types that all spawn in the world on all mapgens but v6.

Wilhelmines Living Floatlands
Liil

Adds various prehistoric animals to your Floatland Zone, if you are using V7 Map Generator.

Wilhelmines Living Desert
Liil

Adds plants to the default deserts of minetest game.

Wilhelmines Living Jungle
Liil

Adds a new type of dense jungle biome to your world

Wilhelmines Natural Biomes
Liil

Adds 9 new biomes

Amethyst
alerikaisattera

Amethyst, basalt, calcite and related building blocks

Loria (alpha)
siegment

Survival in hardcore acid-alien sci-fi themed world

Baked Clay
TenPlus1

Adds the ability to bake clay into blocks and colour them with dye.

SkyRealm for NodeCore
Warr1024

SkyBlocks inside vanilla NodeCore

Aotearoa
Eris

Fork of aotearoa by Dokimi. Complements the default map biomes with Aotearoa, land of the long white cloud, New Zealand.

Warning: Non-free media.