mTimer
Linuxdirk

Ingame timer for showing current playtime, current day time, ingame time, etc.

verbana
fluxionary

verification and banning

silence
fluxionary

adds a node to silence nearby sounds

Renewable Fireflies
mecha_moonboy

Registers an ABM on some ground blocks that spawn fireflies if certain criteria are met.

NodeCore Sharks
GreenXenith

Hammerhead "sharks" for NodeCore

Death Swap
Jo5629_

Switch places with someone random.

Stent
AFCM

A formspec based arena entrance type for arena_lib

Global Patterns
Albert-Dimensioner

Place a node to generate a pattern from that node using that node

HTML to Luanti Hypertext
1F616EMO

Convert HTML to Luanti Hypertext for formspecs

Petroglyph Maker
Neuromancer

Create your own petroglyphs on Desert Stone

Go
LMD

A game of Go

Chat Anticurse
lag01

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

CentralAuth
1F616EMO

Player account unification across Luanti servers

Cartographer for Repixture
Hugues Ross

Adds regional maps that you can craft and place (Repixture version)

More Coral
Nathan.S

Adds coral in more colors.

Signs Redux
sorcerykid

Signs Redux is a complete rewrite of default signs that adds many new features

Cid Music Player
ekl

Plays music

anarchy
solsword

Anarchy PCG library (see https://cs.wellesley.edu/~pmwh/anarchy/lua/ w/ docs at https://cs.wellesley.edu/~pmwh/anarchy/lua/docs32/index.html)

PvP Control
mike.monkeybiter

Allow players to set their own ability to hurt or be hurt in PvP, by chat command or by pressure pads. Nametag colour changes to reflect status.

@-Chat
orwell

Adds an alternative Private Message (PM) system

superspeed
Giga_M

change the player's speed x10

LocalChat
qPexLegendary

Adds local and global chat

Nyan Cat Redo
Blocky Player

nyan lazer, nyan soda and sugar. What's not to love?

filter++ lib
rstcxk

provides an API for filtering text

Error Mail
1F616EMO

Send mail to the admin with error traceback

Lua Button
IlzumiZeminori

Button that executes custom lua code on rightclick

Obdy
Sires

Adds some pretty OP tools :)

Obelisk - Obelisk.jar [Inspired by lizardmeninc Obelisk]
colon

shhh it's here.

Explosion proof obsidian
Miner34

Adds an explosion proof obsidian.

Item Limit
LMD

Limits the amount of items of certain types in player inventories

NC Pumbob
Winter94

adds carvable and sealable pumice bobbers/floaters

Matterbridge Player Events
cj_clippy

Sends a message to the matterbridge when a player joins/parts

Temp Privs
ChimneySwift

Overwrites the default grant, grantme and revoke chatcommands to add revoke or grant expiration.

description_monoids
fluxionary

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

Diamond Arts
Teltalila

Adds decorational fake diamond blocks.

Vignette Redo
kestral

Optionally place a vignette filter over the screen.

ping
Giga_M

show your ping

Player Settings
1F616EMO

Player-specific settings

Timed World Modifiers library
karamel

Environmental ABM that could be triggered on a very wide range of nodes but only a few at a time.

Batch Screwdriver
niwla23

With this you can rotate all nodes in a row at once