Jupiter is a customizable decentralized network. It is based on the Nxt blockchain and developed by Jelurida.
The reason Darcrus chose for this private blockchain approach is the enormous fee costs businesses would have to deal with in case an existing public blockchain would have been used. That would not be economically feasible.
Jupiter tokens which are needed by the software to store data, are not publicly tradable. They are provided by Sigwo Technologies to businesses after purchasing any offering built on Jupiter.
Furthermore, a decentralized encrypted messaging system, also fueled by Jupiter tokens, is available within the Jupiter client itself. This is very suitable for replacing centralized internal communication applications.