flinv
Luke

API to add new inventory tabs which work across different inventory mods

MFSM Multiple Finite State Machine
Sumi

Allows for multple states to be active, while maintaining typical state machine behavior. Good for gamestate and mobs.

Select Item
Wuzzy

Allows other mods to add a simple form to choose a single item.

Smart Chat
Clyde

A new, lightweight, simple and modular Chatsystem

Wield Events
mt-mods

Events for wield item switching

Squill
Luke

A subset of SQL. No complex installation required.

Anti Exploit
LMD

Protects against exploits

Weapons API
Stix

Adds an API to easily register custom weapons

Virt
frogTheSecond

A library for (qemu) virtual machines

ConfigFileLibrary
Tomlaus

A library that allows loading and saving data from config files.

Face Objects
1F616EMO

Calculate the facing of objects

Multiblock Lib
Mindcool25

Multiblock structure handler

PostgreSQL Library
Tomlaus

Library for PostgreSQL Db.

Advanced Rangefinder
sorcerykid

Extends the Minetest API with search capabilities for entities

HTML to Luanti Hypertext
1F616EMO

Convert HTML to Luanti Hypertext for formspecs

Operating System Detector
TPH

Checks the OS of the device running the mod.

Complete and Total Lua-Only Inventory Rewrite
Noodlemire

Creates a completely custom inventory system, which doesn't rely at all on any of the usual UserData objects.

Phonics Library
Neuromancer

Provides a library for creating Phonics (Learn how to read) mods in different languages.

toolcap_monoids
fluxionary

an API to allow multiple sources to apply changes to a tools's capabilities.

Shop Dialog
1F616EMO

Formspec-based shop dialog

description_monoids
fluxionary

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

Echo
1F616EMO

In-game notification system

Chat Games API
Impulse

An API to build chatgames like those in the chatgames

More vector helpers
Hybrid Dog

Adds more vector functions.

Timekeeper
sorcerykid

Timekeeper acts as a centralized dispatcher for all time-sensitive routines

Flow Extras
lazerbeak12345

An experimental collection of extra widget APIs for flow

Extended Protection
1F616EMO

Extended interaction restriction rule

CentralAuth
1F616EMO

Player account unification across Luanti servers

action queues
fluxionary

provides an API for queuing things for batch processing w/ various ways to specify the batch "size".

DataMiner
sorcerykid

DataMiner is an analytical tool for server operators with a feature-rich API for customized report generation

IntelligenceFramework
PlamiumAI

Provide an AI RNN API for developers.

afk_api
fluxionary

an API for registering events which trigger when a player goes AFK or comes back from AFK.

Debugging Console
sorcerykid

Provides an in-game HUD to easily monitor debug output

Telegram
neko259

Integration with telegram messenger chat

Tips
1F616EMO

Send tips to newcomers

verbana
fluxionary

verification and banning

item_monoids
fluxionary

an API for controlling item properties via monoids

Player Settings
1F616EMO

Player-specific settings

Gettime
1F616EMO

A api to get in-game hour/minute

DeltaTime
SkyBuilder1717

Adds deltatime API