Manny
ElCeejo

Adds Manny from that one Reddit post.

No Lag
AFCM

[April fool's joke] Removes Lag

M.Y.K.O.T.A
Xevin

Adds M.Y.K.O.T.A self-propagating mushroom liveform

Whiter List
AntumDeluge

Restrict server access to only whitelisted players

Player_join
Elysian

Adds a custom join and a left message.

Last Login Signs
fgaz

Adds signs that show the last login of players that right-clicked them

Condensed Cobblestone
1F616EMO

81 cobbles in one item!

Itemstring Viewer
Holly Mae

Displays full itemstring of a held item

BetterPM
SonoMichele

Improves private messages and makes them more customizable

Holoemitter
BuckarooBanzai

Holo emitter mod

Mudsling
Avicennia_g

Inverted-direction player slingshot

Formspec AST
Luke

A library to help other mods interpret formspecs.

Fake unknown node
orwell

Adds a node that looks like an unknown node

YL Matterbridge
AliasAlreadyTaken

Handles chat between Luanti and Matterbridge

Dice
Wuzzy

Decorative dice blocks which face a random direction.

Awards STL
vejou

Adds awards to Stellua, and an API to register new ones. Based on Rubenwardy's Awards.

Playtime Recorder
Lejo

Use /playtime to get the time you played

Tell
octacian

Message offline players

Floppies
ROllerozxa

Throwable floppies... That's what they're used for right?

UndoMistakes
mi.sh

You can undo Mistakes, such as stripping Wood

Custom Chat Prefixes
Impulse

Adds Custom Chat Prefixes, you can choose a prefix and colour.

Cross-Section
Silver Sandstone

Cuts the world in half.

ServerSay
Truemmerer

Write in the Chat as the server

Text Text.
olive

Replace textures of nodes with their names.

Minetest Discord Webhook
activivan

Mirror your in-game chat to Discord using webhooks

Cloud Items
Panquesito7

Powerful cloud tools.

Warning: Non-free media.

Biome Lib
mt-mods

The biome spawning and management library.

Cycle Limit
LMD

Limits hotbar slot switching

J_Mute
j45

Mute players that are spamming.

Loot Crates
ElCeejo

Adds randomly spawning loot crates.

Simple Dialogs
Kilarin

Simple Dialogs allows you to add dialogs for npcs and other entities, controlled by an in game text file.

Tardis
iarbat

Adds a functioning space-time machine from the tv show doctor who.

Spawners
SaKeL

Adds spawners for mobs, dungeons, temples and ores.

Disco trains
sivarajansam

Adds colorful subway trains to advanced trains

FakeLib
OgelGames

Fake userdata library

Unicode Text
erle

This library can be used to render UTF-8 encoded Unicode text to a texture (e.g. with tga_encoder). It is intended to be used from code that needs to render in-game signs.

VoxeLibre Shader Preset Port
QBSteve

Enable VoxeLibre's shaders preset for other games.

Scientifically Accurate TNT
AwesomeDragon97

Fixes some of the shortcomings of the original TNT mod.

Dreambuilder Game
mt-mods

Dreambuilder is my attempt to give the player pretty much everything they could ever want to build with, and all the tools they should need to actually get the job done.

Magic Materials
mt-mods

A mod providing common resources and shared magic system for modpacks like gadgets_modpack, bweapons_modpack, and possibly others