Repainter and rotator
MatyasP

Add tools for editing node param2 for different color and different rotation

Name Hider
Shara

Hiide player names

Splink Storage
Yoreni

Adds items that can store massive amounts of other items in your inventory

TPH's Notenodes
TPH

Provides musically charged nodes for playing music - unique instruments + options

Shop Dialog
1F616EMO

Formspec-based shop dialog

Server Cleaner
AiTechEye

Keep the server clean and simple

Tool Crafter
508linx

use any posible material craft tool in crafttable

My Stacks
Don

Changes the max number of items in each stack

description_monoids
fluxionary

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

DTools
Logikí

this gives tools for developers

Job Control Mod
sorcerykid

A more flexible alternative to the builtin minetest.after function

craftsystem
fluxionary

craft registration API which automatically deals w/ replacements

Nodecore Fairy Chimneys
Winter94

Adds geological formations called 'hoodoos' or 'fairy chimneys' to your worlds.

Colored Stone
Clyde

provides colored stones.

node entity queue
fluxionary

a queue for spreading out the generation of node entities over multiple server steps (smartshops, signs, itemframes, etc).

Display
SkyBuilder1717

Adds command to display URL images.

Debugging Console
sorcerykid

Provides an in-game HUD to easily monitor debug output

Spawnarea
Casimir

Players spawn and respawn within an area around the center of active players.

Copy From Chest
zeronumbers

Adds server command copy-from-chest that copies items from chest at x y z to player.

titou nicknames
titou4

test

toolcap_monoids
fluxionary

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

Pink Lava
TenPlus1

Adds pink lava to certain depth of map with new mahogany obsidian block

Toki Pona for NodeCore
nycki93

Adds toki pona glyphs (sitelen pona) to NodeCore.

Tips
1F616EMO

Send tips to newcomers

Color my items!
Sofik5800

Color your items with one command: Color me!

Purple ore
X-DE

Adds new purple ore to floating islands and caves from height 200 to 31000.

Math blocks
Giulio

Adds decorative math blocks to help in teaching

Scripted World Editor
Neuromancer

API that allows you pass in scripting tables to fill a series of shapes of different sizes with different nodes

hexcol color picker
Mjokfox

color picker for hexcol

Server Essentials
jolethen

An essential mod for any server

Fly-B-Gone!
Hugues Ross

Hides butterflies/fireflies

Quarry Link
gabriel1379

Enables use of Quarry Mechanics with the stone-like and resource-nodes of other mods.

Archipelago for Citadel
Warr1024

Connect Citadel to Archipelago Multi-world Randomizer

Mesecon Node
1F616EMO

Make all node have mesecon_wire version

Bedrock Markup Language
sorcerykid

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

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.

Server News
Shara

Show server news when players join

Admin mailing list and report
1F616EMO

Add mailing list for admins and moderators, and a report function

Unstable Caves
M BLOC

Some stones may cave in if punched, making underground expeditions more risky.

Worlanti
SkyBuilder1717

Recreation of the word game in Luanti, with some online features