Ben's Drop Randomizer
MissingTextureMan101

A game agnostic node-drop randomizer

Roadmarks
LukeOfficial

Adds road marks.

Auth Redux
sorcerykid

Auth Redux is a drop-in replacement for the builtin authentication handler of Minetest

Stopwatch
sorcerykid

Stopwatch is Lua-based benchmarking API for Minetest developers

Inotify
ApolloX

A notification tool for players in-game.

Bitwise Operations
sorcerykid

A pure-Lua implementation of common bit-manipulation functions

Darks
_Xenon

Adds dark stuff

Lua Button
Zemtzov7

Button that executes custom lua code on rightclick

Colored Steel
cd2

Adds colored steel blocks.

One For All
mt-mods

bans all players if one dies

Prejoin Messages
Gregon

Notifies players when a player starts connecting to the server

Chat Visual
Itz-Noah

Need a way to distinguish between staff and players?

This should be make sense!
1F616EMO

Adds missing crafting recipes that should exist

AFK Kick (AFK Indicator)
1F616EMO

Kick inactive players

IRC Commands
ShadowNinja

Control your server from IRC

Riddance
Blockhead

Hide or rid yourself of unnecessary items from games and mods without any code

Chat Anticurse
lag01

Kick player out when they type a curse word in chat or using /me or /msg command.

Usable Nodes
Volik

Adds usable nodes, such as kill block, or move block.

Tips
1F616EMO

Send tips to newcomers

Babelfish Redo
1F616EMO

Translate chat messages into other languages

Localized Server News
ronoaldo

Display localized server news when a player joins

Minetest HTTP API QoS control queue
SX

Improve quality of important HTTP requests by grouping requests into service quality buckets.

toolcap_monoids
fluxionary

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

Kill Button
niwla23

Allows you to kill yourself from the UI

status effects
fluxionary

api for defining player status effects

verbana
fluxionary

verification and banning

Database Manager
AFCM

Database Manager API

Japanese Name
Logikí

transform your player name to japaNESE (joke)

Level API
Hypernoot

A library for games to load levels defined as schematics

Dialog Redo
1F616EMO

Flexable dialog API

B.W Protection
Logikí

This gives API for bad words detection

SmartFS
rubenwardy

A library to allow mods to make Formspecs, a form of GUI, easily.

Caps Alert
ANAND

Catches chat messages with all-caps and warns / kicks players.

Offline Phantoms
Kimapr

Players leave "phantoms" when leaving; other players can take items from those

Server Lockdown
1F616EMO

Keep non-admin players away during maintainence

Oddly Sized Checkerboard Testnodes 2
erle

Adds oddly sized checkerboard test nodes.

Tool Watcher
j0j0n4th4n

Introduces an item for monitoring the wield tool durability and alerting players when their equipment is close to breaking through a HUD text.

Stent
AFCM

A formspec based arena entrance type for arena_lib

balanced diet
fluxionary

api for specifying multiple dimensions to eating

MFSM Multiple Finite State Machine
Sumi

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