Up And Down And All Around by Mysteryem
Mod that lets you change the direction of your gravity
Up Mod by Void
A mod that will allow you to upgrade your character and use abilities for your own purposes
Up-Sizer by The_Wabbit
Lets you increase the max stack sizes of Minecraft items.
Update Checker by Tminor1
Will check for an update for Fun Craft Mod Pack 2.
UpdateCheckLib by makamys
A library mods can use to check for updates and display the results in a common interface.
Updated Blocks by Russia9
This mod adds blocks from new versions, for example concrete, andesite or granite.
Updatifier
Easy to use update checking for Sponge plugins.
UpgradableSwords
A mod that allows Vanilla Minecraft Swords to be upgraded into stronger swords.
UpgradeDustMod_1.12.2 by Alexi, MCreator
UpgradeSwords
Adiciona Novas Swords
Upgradeable-Armors by User, MCreator
Upgraded Armaments by 维生素
Backports the feature from 1.15 that allows quickly setting your spawn point without sleeping.