Light Tool
Extex

Adds a tool and api that creates beams of light

Fireworks Redo
niwla23

Adds some better looking fireworks

Lava Stuff
LandarVargan

Adds lava armor, tools, and blocks

Meseport
ForbiddenJ

Allows for the creation of Meseportation systems.

More Ores
Calinou

Adds new ore types.

Less Dirt
DrFrankenstone

Adjusts textures so rolling hills have less exposed bare dirt.

Mesecons Windows
Wuzzy

Adds 3 glass blocks which change their transparency when supplied with Mesecons power.

Dwarf Fortress style caverns
FaceDeer

Adds vast underground caverns in the style of Dwarf Fortress, complete with underground flora in diverse biomes.

Digilines
Jeija

This mod adds digiline wires, an RTC (Real Time Clock), a light sensor as well as an LCD Screen.