Ethereal NG
TenPlus1

Adds many new biomes, items and mechanics into the world.

Nether
PilzAdam

Adds a deep underground realm with different mapgen that you can reach with obsidian portals.

Technic
RealBadAngel

Extensive machinery mod with electricity and ores.

Extra Biomes
CowboyLv

Adds extra biomes, while keeping its looks close to the vanilla MTG

Plantlife
mt-mods

Adds various kinds of plants, fruit bushes, fallen trees, and a whole host of foliage and other ground cover.

pathv7 redo! (Mapgen V7 only)
1F616EMO

Creates a worldwide network of paths, bridges and tunnels.

Caverealms Lite
Shara

A mod for Minetest to add underground realms.

Dungeons Plus
EmptyStar

Decorates dungeon rooms with unique layouts and features

Wilhelmines Living Jungle
Liil

Adds a new type of dense jungle biome to your world

Technic Plus
mt-mods

Technic fork with focus on features and stability

Swamp Biome
Atlante

This mod adds a new swamp biome, with mangrove trees, mud and more!

Native Villages
Liil

Adds villages of native people to the world.

Pyramids (with treasures)
Wuzzy

Pyramids with treasures!

Other Worlds
TenPlus1

Adds asteroid layers and height-based skybox switches to create space environments.

Nether
Hybrid Dog

The underworld for Minetest.

Australia
demon_boy

Adds a wide variety of Australia-themed biomes and content

the curse of the corngirl
Soundwavez

adds a creepy cornfield, with a dark secret...

Baked Clay
TenPlus1

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

Algae
Just_Visiting

Algae mapgen addition to "Minetest Game"

Wilhelmines Natural Biomes
Liil

Adds 9 new biomes

Wilhelmines Marinara
Liil

adds water structures and coral reefs to the oceans of your world

Rail Corridors + Treasures
Wuzzy

Adds simple underground mines with railways and occasional treasure chests.

Shipwrecks
mt-mods

A simple mod that adds various shipwrecks with treasures into the ocean

Technic Plus Beta
mt-mods

The technic modpack extends the Minetest game with many new elements, mainly constructable machines and tools.

The Lower Road
Deadlock

Adds a long road from -Z to +Z to the world, during world-generation.

Ore Deposits
Tarruvi

Adds ore deposits that can randomly spawn on stone

Sunset Biomes
RisingLeaf

Adding two biomes and stuff around them.

Cloud Items
Panquesito7

Powerful cloud tools.

Warning: Non-free media.

Ruined structures
X-DE

Adds ruins to desert, sandstone desert, icesheet, snowy grassland, taiga, rainforest and tundra

Wilhelmines Living Desert
Liil

Adds plants to the default deserts of minetest game.

Wilhelmines Living Floatlands
Liil

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

Livingcaves
Liil

Adds more life to the caves of your world

More Structures
ClothierEdward

Adds several new structures to make your world more alive.

Quartz
Evergreen

Adds quartz ore and some decorative quartz blocks

Caverealms
HeroOfTheWinds

A mod for Minetest to add underground realms.

Fireflies
Shara

Adds fireflies which can be caught in a net and placed in bottles for lighting.

block physics
GigaByte

Add pieces of broken blocks when breaking them.

Badlands
AwesomeDragon97

Adds the badlands biome, which contains plentiful clay and gold.

Nssb
TenPlus1

BIOME integration for nssm, the not so simple buildings.

In the Fog
Jo5629_

Herobrine has entered your world.