None of them are ready to use in a serious capacity yet. However, Sia's network has been live for 2 years now, and people are forming smart contracts, getting paid to host data, and backing up real files on the network. The fundamentals are solid -- it's just Bitcoin with one extra transaction type -- but there's a lot of potential left to be explored.
Based on the Filecoin announcement, they are building something very similar to Sia. It appears to depart from traditional Bitcoin proof-of-work consensus though. I'm looking forward to reading their whitepaper.
Based on the Filecoin announcement, they are building something very similar to Sia. It appears to depart from traditional Bitcoin proof-of-work consensus though. I'm looking forward to reading their whitepaper.
Disclaimer: I'm one of the co-founders of Sia.