Sticks Stones
MikeRedwood

Makes Sticks from leaves and scatters small stones

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.

Purple ore
X-DE

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

Archaeology
SkyBuilder1717

Adds an looting and API in archaeologing

Tac Nayn
GreenXenith

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

Spawn redo
cathaya7d4

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

Beautiful Boulders
regulus

Procedurally Generated Rocks with (pretty) Accurate Collision Boxes

Fragments
Amaz

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

Fly-B-Gone!
Hugues Ross

Hides butterflies/fireflies

golden lava
Giga_M

add golden lava

treasures
ademant

Treasure nodes with useful items

Obdy
Sires

Adds some pretty OP tools :)

Floof
Momo

Add BicBiomeCraft inspired biomes, tools, and items.

Silver
Jackknife

adds silver ore and tools

Mud
Blocky Player

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

Too many ores
TeufloV

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