Games with a creation-sharing side

[Corrupted Unicorn]

What am I talking about? Games that let you create something and share it with other players! 

Think for example, of Spore: how you could save your creatures and creations as PNGs to share them with other users so they could have them in their game. They even had the Sporepedia, an official online platform where you could submit your creations.

While I'm trying to stick to games that "officially" let you create and share stuff, I think I should also mention the oooooodles of "custom content" you could get for any version of the Sims! I can't really say if it's officially endorsed by Maxis or not, but they seem to have a knack for these things 

There's also Animal Crossing, especially later versions: you can share custom patterns, clothes, and send a dream version of your town/island for other players to explore 

What other games do you know that let you create things and share them with other users? Or perhaps you know a deep and interesting modding community, even if unofficial? Please, let me know! 

[Furbisms]

Minecraft: You can export and share world files.

Sonic adventure/adventure 2 (Steam only): You can export files for your chao and share them using krzys2's chao importer/exporter, or chao editor.

Wobbledogs: You can share codes to import your wobbledogs.

Star garden: You can share your lumi files.

I'm looking for more of these as well because I want to host these sort of things on my website. Do you know if animal crossing new leaf's QR codes still work, or do you need to use some kind of homebrew internet server to share them? I'm out of the loop on how internet works on the 3ds now, so if the QR codes just work without it that would be nice  Same with new horizons, I'm not paying for nintendo switch online currently. Although I do think those need online to share