WorldEdit
sfan5

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

Digtron
FaceDeer

Adds components for building modular tunnel boring machines

Edit
Johannes Fritz

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

I Have Hands
SURV

Carry nodes/blocks with inventories without breaking them.

Unified Dyes
mt-mods

Unified Dyes expands the standard dye set from 15 to up to 256 colors (depending on the object to be colored)

Placement Preview
SURV

shows a preview with orientation of the node the player is holding.

Better Screwdriver
12Me21

A more intuitive node rotation tool

Terraform
x2048

Adds terraforming tools to your creative toolbox

Tower Crane
joe7575

A scaffold alternative for your building site

Torch Bomb
FaceDeer

Place torches throughout your entire surroundings with a torch bomb

Area Containers
jwmhjwmh

Adds nodes that contain areas in which you can build

Randungeon
Phii

adds highly randomized vivid dungeons to the world, and tools to spawn/customize them.

Industrious
StarNinjas

Adds new industrious-themed blocks and tools.

Streetbuilder
seckl

Build a street from given points

Extruder Tool
fgaz

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

Research N' Duplicate
Noodlemire

Obtain and research enough of a specific item to unlock the ability to infinitely duplicate it.

WorldEdit Additions
Starbeamrainbowlabs

Extra tools and commands to extend WorldEdit. Currently has over 70 commands!

new minerals
GigaByte

new minerals for armor and tools,add mineral abysmal, cobalto,adamantita,tugsteno,clorofite,titanium and more uses for obsidian

Pontoons
FaceDeer

A "floating" block that can be placed at the surface of a body of water without needing to build pilings first.

Wrench
mt-mods

Adds a wrench to pick up nodes with inventories, such as chests, and transport them to another location.

Omnidriver
OgelGames

The ultimate screwdriver.

mcl_edit_signs
cora

Edit signs in mineclone2

Imaging
entuland

An image / bumpmap importer mod

Visual Bots
Nigel

Visually programmable turtle bots

VoxelForge - Breaking Changes soon.
VoxelForge

Build, Fight, Mine, and so much more. A MineCraft Inspired game, focused on being fun, adding good features that Mojang decided against using, and being performant

The Build Spawner
Thunder1035

Gives build spawner for spawning builds which makes city creation easy

Stripped Trees
1faco

Adds Stripped tree trunks.

Wings
xXNicoXx

Wings is a mod whiche allows server owners to give players fly privs while holding the wings (Like binoculars) made by xXNicoxx

Stone Age Integration Pack
csirolli

Adds basic stone age & survival tools and makes the start in the world harder

Cozy Lights
SingleDigitIq

Early alpha. Improves the way light sources(torches etc) behave and allows to create huge lights, literal projectors with just a mouse click, light map will be computed for you.

Scaffolding
Semmett9

Adds wooden and Iron scaffolding.

Balloon Blocks
TBSHEB

Adds balloon blocks that can be placed on air.

Better Locks
SkyBuilder1717

Adds locks and locked doors

Extra Wool Stuff
Impulse

Adds more wool items and nodes

Replacer
Sokomine

Exchange/replace nodes with one click.

Trails
X5Dragonfire

Allows you to make paths in grass with ground roller

Nodecore Paint
Kimapr

Paint anything on node surfaces

Fast Build Tool
playduin

Tool for fast box building

Block Exchange
BuckarooBanzai

Cloud worldedit schema exchanger

Quarry Mechanics
kestral

Adds quarry mechanics to stone nodes.