craftsystem
fluxionary

craft registration API which automatically deals w/ replacements

More vector helpers
Hybrid Dog

Adds more vector functions.

Chunk Version
Sumi

Stores the numerical version a chunk was generated, so that other mods may query this.

Sway
lazerbeak12345

A simple inventory that makes use of Flow forms.

Star
Wiz

A* Pathfinding algorithm implementation

Archipelago Library
Warr1024

Archipelago multi-world randomizer integration library

Lockbox
Jo5629_

Library for cryptography/encryption functions.

Autobox
Just_Visiting

Auto Collision/Selection Loading Boxes

Mapsync
BuckarooBanzai

Synchronize the ingame map with a lua-backend

Antigrief
sorcerykid

An API for validating node and item placement via a simple callback mechanism.

Japanese Name
Logikí

transform your player name to japaNESE (joke)

node entity queue
fluxionary

a queue for spreading out the generation of node entities over multiple server steps (smartshops, signs, itemframes, etc).

HTML to Luanti Hypertext
1F616EMO

Convert HTML to Luanti Hypertext for formspecs

AoM Settings
Sumi

Provides methods for both player level and server level settings

deploader
LuantistDork

Simple mod API that automates dependency-specific behaviour using a folder-heavy approach.

DeltaTime
SkyBuilder1717

Adds deltatime API

AFK Indicator
1F616EMO

API to check player AFK status

Dialogs
1F616EMO

Dialogs with options

Debugging Console
sorcerykid

Provides an in-game HUD to easily monitor debug output

Weapons API
Stix

Adds an API to easily register custom weapons

balanced diet
fluxionary

api for specifying multiple dimensions to eating

Advanced Forceload
Kimapr

a better forceloading API

Seasons Clock
solsword

API for getting various "season" parameters based on server time and a few customiable settings. Doesn't change gameplay; just a library that other mods can use to do seasonal things.

Isogen
BuckarooBanzai

Generate isometric images from ingame builds

Minebase Core
ThatCommand

Adds APIs and new dynamic functionalities.

Luarocks Wrapper
lazerbeak12345

Securely Wrap Luarocks packages without needing trusted mods.

Level API
Hypernoot

A library for games to load levels defined as schematics

description_monoids
fluxionary

API to allow multiple mods to make modifications to an itemstack's description

Priority Queue
Wiz

Associate items with priorities to order them.

Persistent Effects
epCode

An API for creating persistent effects for any object. eg. damage a player or entity over time. (like poison)

Anti Exploit
LMD

Protects against exploits

Lush
rstcxk

fully featured shell interpreter

CentralAuth
1F616EMO

Player account unification across Luanti servers

Trucraft
mt-mods

An alternative crafting system done entirely in the world.

Advance ore API
Sere Motsatt

Create complex minerals the easy way

NameGen
cronvel

Name generator API.

Face Objects
1F616EMO

Calculate the facing of objects

YL Scheduler
AliasAlreadyTaken

Execute tasks based on utc

imfs
Signal_

An immediate-mode, functional, reactive abstraction around Minetest's formspec system.

Quest Framework
TeTpaAka

Simple framework to define quests.