Priority Queue
Wiz

Associate items with priorities to order them.

Weapons API
Stix

Adds an API to easily register custom weapons

Debugging Console
sorcerykid

Provides an in-game HUD to easily monitor debug output

Advanced Breath and Health APIS
liteninglazer

Creates APIS to allow different players to heal health and allow different players to breathe different items.

Cid Music Player
ekl

Plays music

Guider
1F616EMO

HUD markers for navigation

Fbt Core
Forburnt

A set of utils for other fbt_* mods

Multiblock Lib
Mindcool25

Multiblock structure handler

PostgreSQL Library
Tomlaus

Library for PostgreSQL Db.

filter++ lib
rstcxk

provides an API for filtering text

more_player_monoids
fluxionary

more player monoids

Item Holders
Jose_ManuelS18

Adds 'Item Holders', blocks that hold your items in display, also provides a API.

Star
Wiz

A* Pathfinding algorithm implementation

MFSM Multiple Finite State Machine
Sumi

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

Wield Events
mt-mods

Events for wield item switching

action queues
fluxionary

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

Stent
AFCM

A formspec based arena entrance type for arena_lib

description_monoids
fluxionary

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

Select Item
Wuzzy

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

Advance ore API
Sere Motsatt

Create complex minerals the easy way

status effects
fluxionary

api for defining player status effects

Compression Lib
The4spaceconstants

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

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.

Sway
lazerbeak12345

A simple inventory that makes use of Flow forms.

Bedrock Markup Language
sorcerykid

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

flinv
Luke

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

craftsystem
fluxionary

craft registration API which automatically deals w/ replacements

Key Binding
1F616EMO

Register callbacks when a key is pressed, holded, or released.

Noriel Sylvire's Minerals Core Modpack
Noriel_Sylvire

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

Smart Chat
Clyde

A new, lightweight, simple and modular Chatsystem

aSignals
Sumi

Signal event bus API including SIGNAL, LISTEN and CONDITIONAL functions

Random API
TheFanne

Provides a simple-to-use framework for selecting random objects with probabilities

Lush
rstcxk

fully featured shell interpreter

VizLib
OgelGames

Visulization Library

Smart Vector Table
Noodlemire

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

Wield Gadgets
1F616EMO

Register gadgets that can be used with a hotkey

rcsv
Wuzzy

RFC-4180-compliant CSV parser and writer

Node Damage
Noodlemire

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

item_monoids
fluxionary

an API for controlling item properties via monoids

Shop Dialog
1F616EMO

Formspec-based shop dialog