Hoardercraft is a collection of mods whose primary aim is to help you hoard every single little item you ever generate in Minecraft. Why? Why not?! Seriously, those feathers could be really useful some day! Have all the yellow dye you'll ever need but still have 100's maybe 1000's of dandelions? Keep 'em! You never know, they could be part of a defense for the zombie apocalypse that every one seems to think is coming...
Current HoarderCraft related mods:
Upsizer: does one thing -- it up-sizes or increases the max stack size per slot of various Minecraft items in inventories (player, chests, hoppers, dispensers, etc.). For an overview and installation requirements see the CurseForge overview page at http://minecraft.curseforge.com/projects/upsizer-mod.
Super Blocks: gives you ways to compress standard blocks and items into super versions which you store in standard chests for uncompressing (uncrafting) at some later time. Always wanted to carry 1 million blocks in the palm of your hand? Yea, now there's a mod for that! For a splashy-pretty-pictures-included overview, recipes, and installation requirements see the CurseForge overview page at http://minecraft.curseforge.com/projects/superblocks-mod.
Vanilla Food Pantry: gives you new uses of and way better storage for all those farmed crops and animal drops. We've got bags of stuff, BIG bags of stuff, and cartons of bags of stuff!
For mind-numbing development details for any of these mods, see this project's wiki and issue-tracking pages.