Better Command Blocks
ThePython10110

Adds command blocks similar to those from a certain other voxel game.

Ancient Fertilizer
Daniel

Adds ancient fertilizer, sourced from ancient stone in the underground, useful for farming flowers if you need dye for colored nodes, complements bonemeal.

Hardcore Farming
Neuromancer

Makes farming a hardcore challenge by adding very hungry pests. Can you overcome them or will they defeat you?

Axis Tools
mt-mods

All the functionality of tinkers construct, but all in your inventory.

Frame
sofar

A stylish item and node frame that causes no lag/server load.

Pigiron
TenPlus1

Adds pig iron ingots which need to be crafted to make steel, also blocks and stairs.

Placeable Buckets for Catching Rainwater
Noodlemire

Allows empty buckets to be placed as nodes in order to collect rainwater.

Mob Crab (Beta)
Can202

Adds Crabs.

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.

Clay Bricks
AwesomeDragon97

Adds colorful clay bricks.

Minetest Uni Library
fatalerror420

Adds b3d reading (and interpretation), binary reading, media filepath location, an extensive Love2d math library, and more.

Moonflowers
karlexceed

Adds a rare pale blue flower that glows faintly in the darkness.

Digicontrol
OgelGames

Adds nodes to control the flow of digiline messages

Swamplified
Neuromancer

This mod adds a few more nice touches to Atlante's Swamp biome mod

Researcher
EmptyStar

Research items to unlock duplication

Chocolatestuff
lazerbeak12345

Adds edible chocolate tools and armor to Minetest.

Smoke Signals
Just_Visiting

Signal your friends, or warn your enemies!

Infinite Chest
Dragonop

Adds a configurable chest that gives an infinite amount of something.

Lava Ore Gen
Coder12

Makes the lava turn stone into ore over time.

De Nenio
Jolesh

Adds possibilities to get items normally unobtainable in skyblock through new mechanics and objects

Grass String
Skivling

Adds string made from grass, which can be converted into normal string.

Flower Beds
ZenonSeth

Flower Beds for growing flowers

Sedimentology
sofar

A mod that adds realistic erosion and degradation of rocks.

Chains
X17

Adds chains to climb or decorate

Climb Glove
ApolloX

A magic glove which allows you to punch nodes to travel vertically.

Treasurer
Wuzzy

A framework to define and distribute random treasures into the world.

Power generators
SFENCE

Add power generators based on appliances API.

Multitools
ChimneySwift

Adds a series of multi-purpose tools to Minetest

Ore Deposits
Tarruvi

Adds ore deposits that can randomly spawn on stone

Flag Chooser
Jo5629_

Change to a specific flag in pride_flags with this tool.

Rain Barrels and Wells
Piezo_

Replaces overpowered "water generators" with a unique water-harvesting system

Custom Falling Nodes
TenPlus1

Tweak falling blocks to add custom controls

More Pickaxes
Koda_

Adds additional pickaxes to the game

Bricks Plus
X17

Adds different brick patterns

Morebricks
CalebJ

Adds an assortment of new bricks to build with.

TPH's Spyglass
TPH

Provides a Spyglass for zooming in and out (if RMB is pressed)

Meseport
ForbiddenJ

Allows for the creation of Meseportation systems.

Etherium Stuff
alerikaisattera

Decorative stuff using ethereal's etherium dust

Raw Ore Blocks
Silver Sandstone

Adds block forms of metal lumps.

Missions
BuckarooBanzai

Adds blocks to create missions with rewards, timeout and penalties.