Streamr is a crowdfunded open source project with contributors around the world.
Data is stored in the blockchain forever and can be retrieved using a transaction hash as an identifier.
Datacoin is a platform that can be used by applications such as torrent trackers, encrypted messaging services, and can be used to store other kinds of small data - all censorship-free.
Developers can store torrent files, certificates, computer programs, HTML pages and other kinds of meta-information
in the Datacoin blockchain.
Windows users can use a GUI wallet, Linux users should compile datacoind or Datacoin-QT from source (see instructions).
Wallets are in development, and more features are coming soon, but the wallet’s current functionality is similar to other coins.