Spawn redo
cathaya7d4

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

Tac Nayn
GreenXenith

Adds Nyan Cat's evil twin, Tac Nayn (and a gray-scale rainbow).

Beautiful Boulders
regulus

Procedurally Generated Rocks with (pretty) Accurate Collision Boxes

Nyancat's heaven (reworked)
Hybrid Dog

Adds a nyanland in the sky

treasures
ademant

Treasure nodes with useful items

Purple ore
X-DE

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

Dirt Tunneler
Neuromancer

Makes dirt deeper and you can tunnel through it just by walking through it. Press spacebar/shift to tunnel upward/downward with auto placed ladders.

Noriel Sylvire's Minerals Core Modpack
Noriel_Sylvire

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

Unstable Caves
M BLOC

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

Archaeology
SkyBuilder1717

Adds an looting and API in archaeologing

golden lava
GigaByte

add golden lava

Obdy
Sires

Adds some pretty OP tools :)

Mud
Blocky Player

Adds stylish mud blocks and even blocks you can walk through. Setup traps, secret rooms and much more!

Silver
Jackknife

adds silver ore and tools

Too many ores
TeufloV

This adds 53 new ores. But most of them are useless.