WorldEdit
sfan5

In-game world editor. Use it to repair griefing, or just create awesome buildings in seconds.

Protector Redo
TenPlus1

Lets players craft special blocks to protect their builds or disable PVP in areas.

Edit
Johannes Fritz

Allows copying, pasting, filling, deleting, opening and saving 3D areas

Modgen
BuckarooBanzai

mapgen mod creator

Tools Using the Node Damage and Repair System
Noodlemire

Overrides pre-existing tools to make them cause persistent node damage.

WorldEdit Additions
Starbeamrainbowlabs

Extra tools and commands to extend WorldEdit. Currently has over 22 commands!

Terraform
x2048

Adds terraforming tools to your creative toolbox (WIP)

Areas
ShadowNinja

Areas is a advanced area protection mod based on node_ownership.

NextGen Bedrock
StarNinjas

Adds an indestructible bedrock layer at the bottom of the world.

Mapserver
BuckarooBanzai

mod for the mapserver

Playtime Recorder
Lejo

Use /playtime to get the time you played

Blockbomber Editor
MisterE

Make arenas for Blockbomber

Really Flat
rdococ

Generates superflat terrain in whatever material you choose.

Streetbuilder
seckl

Build a street from given points

Internet Relay Chat
kaeza

Connect your server to an IRC channel, and install irc_commands to control the server from IRC

Map Tools
Calinou

Adds various special versions of normal blocks, tools, and other map maintainer tools.

WorldEdit Maze Generator
wsor4035

A maze generator

Extruder Tool
fgaz

Adds an extruder tool that can extend continuous surfaces towards the node face that was clicked

Entity Modifier
j8r

Modify the model and size of entities, including players.

Public teleport location bookmarks
Hybrid Dog

Add commands to manage public positions of interest

Discord-Minetest Relay
archfan7411

Mod + external program providing Discord relaying and commands.

Remove Unknowns
Clyde

A small tool to help you clean up your world of unknown-blocks.

Chest with Everything
ROllerozxa

Adds a chest node containing all registered nodes, items and tools.

Glob Patterns
1F616EMO

Use glob patterns in Lua and in serveral commands

Handle Schematics
Sokomine

A library to make creating and placing saved areas easier.

Arcade3D
Thunder1035

A Pacman inspired game