Xp Storage by BrickMaster5000(SteveBeeblebrox), MCreator
Store your Xp!
XpCrafter
Hydra Mod
Xplosion Core by Big_Xplosion
A core for all the Xplosion Mods
XrayBlock
This Mod adds in a Simple feature which is an X-ray Block that allows you to see through Walls, Ground, Bedrock, And Caves. Crafting Recipe on the Forum post
Xtones by TehNut, Dhvagra, InsomniaKitten
Xtones adds modern/futuristic/fantasy style decorative building blocks.
Xtra Armour Mod
This mod adds armour such as Dirt Armour, Cobblestone Armour, Sand Armour, Gravel Armour, Invisi Armour and much, much more.
Xtra Drinks by Strikeboom, ChauhanSai
Venture into a new world with XtraDrinks. This mod adds new fluids into the game with a new mechanic, dehydration. Explore new structures and craft new foods around the world. You can become the master liquidor. Has support for Tinkers Construct and JEI
Xtra Tools by 2MuchMinecraft
Adds extra tools and ores!