Surprise Blocks
Wuzzy

Randomly spawns surprise blocks closely about ground level.

Petards
IlzumiZeminori

Miscellaneous pyro things

obsidian
GigaByte

more uses for obsidian

Colored Steel
cd2

Adds colored steel blocks.

Macro Crafting Manager
sorcerykid

Macro Crafting Manager provides a streamlined drag-and-drop interface for dividing and arranging item stacks within the craft-grid

Bouncy Leaves
1F616EMO

Adds bouncy and fall damage reduce effect to leaves

Dye Mixer
LRV

This mod removes the mixes of dyes and the crafting recipes that allow you to dye wool and make them craftable in the Dye Mixer.

Noriel Sylvire's Minerals Core Modpack
Noriel_Sylvire

An API for automatically registering recipes, nodes and ore generation.

Random (Useful) stuff
pl608

A library that adds well... Random Stuff

Autobuilder
limafresh

Adds a GUI for building cubes with customizable width, height, and length.

TP Gate
AiTechEye

Teleport through the gate

Openion Yeast
Wovado

Adds Yeast and a Yeast Barrel

Parcdeco
Floatland

adds grass-like nodes that have flowers

Staff Channel
_Xenon

Write messages only to staff

Good Sneaking
zempik10

Makes the player have better sneaking.

TNTTag
debiankaios

A player is holding TNT which is about to explode; they must tag other players to get rid of it

Sugar
X17

Adds eatable sugar made of papyrus and a sugar block

Color Blocks
mt-mods

Contains colored building blocks.

Ben's Gear
MissingTextureMan101

Attach tool parts to create new tools and add a whole new layer of strategy to your tool crafting!

Portal Rail
BigBear

Minecart rail that teleports exactly 500m in direction of travel

Configuration Pack
X17

Contains several node setting changes

Waste
Jolesh

Adds Waste and ways to recycle it into useful resources

Better Roads
DragonWrangler

allows players to make roads with less jagged edges

Invisible Blocks
Truemmerer

Add invisible Blocks

Hardcorebrix
drkwv

Adds durable building materials that won't break on a first dig.

XP Highscores
debiankaios

Add a better highscore system for xp_redo.

nodeu
ulla

metal blocks stair railing coloured

Livetools
AiTechEye

Craft tools which have a life of their own - they can fight, dig, or place for you

news
GigaByte

adds an editable news section when a player joins

Item exchange shop
Krock

Provides a simple exchange shop (currency compatible)

Rotting Wood
Polynium

Causes wood to slowly rot while exposed to water

Spectator Mode
jp

Allows you to watch other players in their 3rd person view.

Drawstruct
Xenon

Draw or generate random structures

Ubertool Mod
HartRend

Provides a combination pick, shovel, and axe tool capable of extreme function. Tool is also illuminated.

Glostone Building Blocks
Wovado

Adds basic glostone-based building materials

Prop Hunt Modpack
Jo5629_

Transform into nodes and with a minigame.

Hero Mines
Neuromancer

Can you rescue the miner trapped at the bottom of the mine? Creates mines that are used as levels for the game H.E.R.O.

3D Spikes
BryanGruik15

Adds spikes to the game.

Fragments
Amaz

A mapgen with a goal, with things needed to advance to the next level.

Spawn redo
cathaya7d4

Drop-in replacement for default/spawn for more third-party biomes