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.

hand_monoid
fluxionary

player monoid for controlling the look and abilities of the player's hand.

CSMT Bots (Obsolete)
Logikí

Add bots to your game for training

Cid Music Player
ekl

Plays music

TPH's Basic Filesystem
TPH

API for loading files into a basic readable format as well as loading and converting conf files

Table Goodies
benrob0329

A small package for extra (can't live without) functions for working with tables.

Bedrock Markup Language
sorcerykid

Bedrock Markup Language is an extensible markup language and API for formspecs.

Compression Lib
The4spaceconstants

A library that provides functions to procedurally register compressed versions of nodes.

Kill Log
Wuzzy

Allows mods to display the recent player kills, deaths and other game events

NucleoTest
DarkXWolf17

Battle Royale-like game. Provides an API and a reference implementation. Highly radioactive. Work in progress.

Smart Vector Table
Noodlemire

API that adds a way to create tables indexed by 3D Vectors.

deploader
LuantistDork

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

Node Damage
Noodlemire

Enables nodes to be partially damaged, and to be repaired afterwards.

craftsystem
fluxionary

craft registration API which automatically deals w/ replacements

Discrete Player API
Hypernoot

A library for games which attaches players to node grid

Minetest Systemd (API)
Piezo_

Debugging utility and compatibility tools for server owners and/or modpack creators

Fbt Core
Forburnt

A set of utils for other fbt_* mods

Function Delayer
Hybrid Dog

Allows executing functions after a delay to reduce possible lag (EDD scheduler?)

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.

Advanced Rangefinder
sorcerykid

Extends the API with search capabilities for entities

Lush
rstcxk

fully featured shell interpreter

Noriel Sylvire's Minerals Core Modpack
Noriel_Sylvire

An API for automatically registering recipes, nodes and ore generation.

timehud
bookgirl

Minimal HUD timer API

Antigrief
sorcerykid

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

afk_api
fluxionary

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

GroupLib
rudzik8

General grouping API

Telegram
neko259

Integration with telegram messenger chat

Minetest Teams
pl608

simple multiplayer team system

Item Tracking
Impulse

Provides a API to mod developers to track which inventories items are in.

Minebase Core
ThatCommand

Adds APIs and new dynamic functionalities.

Isogen
BuckarooBanzai

Generate isometric images from ingame builds

Tips
1F616EMO

Send tips to newcomers

Face Objects
1F616EMO

Calculate the facing of objects

Wield Events
mt-mods

Events for wield item switching

Autobox
Just_Visiting

Auto Collision/Selection Loading Boxes

Node Object
jwmhjwmh

A library for associating objects with nodes

Priority Queue
Wiz

Associate items with priorities to order them.

Multiblock Lib
Mindcool25

Multiblock structure handler

group:any
1F616EMO

Item group applied to ALL items for crafting recipes.

Persistent Effects
epCode

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