Fragments
Amaz

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

Fly-B-Gone!
Hugues Ross

Hides butterflies/fireflies

Noriel Sylvire's Minerals Core Modpack
Noriel_Sylvire

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

Sun Flowers
Hybrid Dog

This mod generates flowers which close their heads at night.

Obdy
Sires

Adds some pretty OP tools :)

Purple ore
X-DE

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

treasures
ademant

Treasure nodes with useful items

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.