Loria (alpha)
siegment

Survival in hardcore acid-alien sci-fi themed world

Ocean
StarNinjas

Adds coral reefs, fish, decorative ocean blocks and much more!

Projectiles
Noodlemire

Adds various projectile weapons which work based off of MT 5.3.0's new collision info provided to objects' on_step functions.

Bridges and stairs, factory-style
narrnika

Adds a steel bridges, railings and stairs in Minetest.

Plastic Box
Starbeamrainbowlabs

Adds a recolourable plastic box. Fork of @cheapie's version with improvements.

Axis Tools
PolySaken

All the functionality of tinkers construct, but all in your inventory.

Trucraft
PolySaken

An alternative crafting system done entirely in the world.

Poly Decor
PolySaken

My spin on decorative stuff.