Wilhelmines Living Jungle
Liil

Adds a new type of dense jungle biome to your world

Baked Clay
TenPlus1

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

Caverealms Lite
Shara

A mod for Minetest to add underground realms.

Wilhelmines Natural Biomes
Liil

Adds 9 new biomes

Randungeon
Phii

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

Too Many Stones
JoeEnderman

18 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.

Melterns
IcyDiamond

Tinkers Construct in Minetest!

Cloud Items
Panquesito7

Powerful cloud tools.

Oxidizing Copper
StarNinjas

This mod aims to make copper/bronze more realistic by making them slowly oxidize into a bluish/green block when exposed to water.

Multiple Biome Generator
chaosomnium

230 Pseudorandomly Generated Biomes, Trees, Fruits, Ores, Tools, and Liquids

Australia
demon_boy

Adds a wide variety of Australia-themed biomes and content

Amethyst
alerikaisattera

Amethyst, basalt, calcite and related building blocks

Wilhelmines Living Desert
Liil

Adds plants to the default deserts of minetest game.

Quartz
Evergreen

Adds quartz ore and some decorative quartz blocks

Darkage - the original plus improvements
addi

DarkAge adds several new nodes and crafts to create a pre industrial landscape.

Gal
ShadMOrdre

A collection of naturally occuring materials, including: sand, clay, dirt, stone, ore, metals, glass, various water types, oil, lava, grease, liquid soils, and decorative stones.

SkyRealm for NodeCore
Warr1024

SkyBlocks inside vanilla NodeCore

Lapis Lazuli
LNJ

Adds lapis lazuli ore, items and blocks.

Deepslate
Silver Sandstone

Adds deepslate and related building materials.

Alien Tools
chaosomnium

Alien Tools Mod for Minetest - adds Alien Tool, Shield, biome, etc

New Horizons
Hi_World

Adds 4 new biomes and TONS of new blocks!

NodeCore Nature: Revised
Warr1024

Updated, fixed, enhanced edition of Winter94's NodeCore Nature

Tac Nayn
GreenXenith

Adds Nyan Cat's evil twin, Tac Nayn (and a gray-scale rainbow).

Obdy
Sires

Adds some pretty OP tools :)

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.