Sia is a decentralised storage platform which is being actively developed.
Users all over the world contribue disk storage from their computers to form a decentralised network. Using SiaCoins, users can rent cloud storage space on the network, and hosts are paid for their contributions to the network.
A combination of encryption, smart contracts and erasure coding ensure secure, private and reliable cloud storage across the network. Because of how Sia operates, it will lower the barrier to entry to cloud stoage.
Sia was recently voted as one of the biggest surprises of 2016 in the cryptocurrency world, outranking extremely popular coins like DAO and LISK.